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I have just come out of hospital and have in the region of 30 e-mails from gmail over the past few days 'linking' a gmail account to my (hotmail) email address. I have not done this once never mind 30 times!
the supposed gmail accounts are made up of random letters and numbers eg vvcxzzx.comvcxzdfgh.com@gmail.com
How do I stop this? Surely someone like google should not be allowing this to happen?
Thanks in advance for any advice :)
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As an exercise for class, I'm creating a class that manages user sessions.
The session details are stored in a database and also there is a $_SESSION[user_id] variable to carry in between pages.
The idea is that it would be hard for an attacker to steal the cookie AND the ip address AND the user agent AND to keep the session refreshing, as I put a limit of 15 minutes.
When the user logs in, the database object is created, then its existence is checked in every page that is visited.
<?php
//Recojo parametros de formulario de logeo
$username = $_POST['username'];
$password = $_POST['password'];
//abro conexion base de datos
$mysqli = new mysqli("localhost", "root", "unir_2014", "wordpress");
if ($mysqli->connect_errno) {
printf("La conexion ha fallado! El servidor responde: %s\n", $mysqli->connect_error);
exit();
}
//----------------------------------------------------------------------------------------//
//----------------------------------------------------------------------------------------// //EXPIRAR
$comienzo = time(); // Momento al logearse
// Le damos un tiempo de expiracion de 1 minuto
$expirar = $comienzo + (15 * 60);
//----------------------------------------------------------------------------------------// //IP ADDRESS
if (isset($_SERVER)) {
if (isset($_SERVER["HTTP_X_FORWARDED_FOR"]) && ip2long($_SERVER["HTTP_X_FORWARDED_FOR"]) !== false) {
$ipadres = $_SERVER["HTTP_X_FORWARDED_FOR"];
} elseif (isset($_SERVER["HTTP_CLIENT_IP"]) && ip2long($_SERVER["HTTP_CLIENT_IP"]) !== false) {
$ipadres = $_SERVER["HTTP_CLIENT_IP"];
} else {
$ipadres = $_SERVER["REMOTE_ADDR"];
}
} else {
if (getenv('HTTP_X_FORWARDED_FOR') && ip2long(getenv('HTTP_X_FORWARDED_FOR')) !== false) {
$ipadres = getenv('HTTP_X_FORWARDED_FOR');
} elseif (getenv('HTTP_CLIENT_IP') && ip2long(getenv('HTTP_CLIENT_IP')) !== false) {
$ipadres = getenv('HTTP_CLIENT_IP');
} else {
$ipadres = getenv('REMOTE_ADDR');
}
}
//----------------------------------------------------------------------------------------// $version_cliente = $_SERVER['HTTP_USER_AGENT'];
//----------------------------------------------------------------------------------------//$query = "SELECT * FROM sesiones WHERE name ='" .$username."'";
if ($result = $mysqli->query($query)) {
while($row = mysqli_fetch_array($result)) {
$salt = $row['salt'];
$passcheck = $row['password'];
$id_usuario = $row['id_usuario'];
$passwordin = md5($password.$salt);
$direccion_ip = $ipadres;
}
//compruebo si la contraseña coincide con el hash almacenado en la base de datos
if( $passcheck === $passwordin){
echo '<script> window.location = "privatecontent.php" </script>';
//if the user has javascript
$url = 'privatecontent.php';
echo '<META HTTP-EQUIV=Refresh CONTENT="0; URL='.$url.'">';
//if the user doesnt have javascript*
//----------------------------------------------------------------------------------------// //INTRODUCIMOS OBJETO SESSION EN LA BASE DE DATOS
//mysqli_query($connection, "INSERT INTO `wordpress`.`session_log` (`id_sesion`, `id_usuario`, `direccion_ip`, `version_cliente`, `expirar`) VALUES ('', '".$id_usuario."', '".$direccion_ip."', '".$version_cliente."', '".$expirar."');");
mysqli_query($mysqli, "INSERT INTO `wordpress`.`session_log` (`id_sesion`, `id_usuario`, `direccion_ip`, `version_cliente`, `expirar`) VALUES ('', '".$id_usuario."', '".$direccion_ip."', '".$version_cliente."', '".$expirar."');");
//la variable de sesion solo almacena la id de usuario en uso, para asociarlo a la sesion de la base de datos
session_start();
$_SESSION['user_id'] = $id_usuario;
}
}
else{
echo '<div id="wrong" class="wrong"> "Nombre de usuario o contraseña incorrectos! <br>';
echo "Haz click<a href='FORMULARIO DE REGISTRO!!!'>aqui</a> para registrarte...</div>";
}
That would be the login manager, now, the check_login class:
<?php
// TODAS LAS PAGINAS DEBEN INCLUIR ESTE ARCHIVO!
//abro conexion base de datos
$mysqli = new mysqli("localhost", "root", "unir_2014", "wordpress");
if ($mysqli->connect_errno) {
printf("La conexion ha fallado! El servidor responde: %s\n", $mysqli->connect_error);
exit();
}
//buscamos el id del usuario activo.
//recibimo de $_SESSION (o sea la cookie del cliente) solo el id del usuario. que usuario dice ser
//si la cookie ha sido robada, lo mas probable es que la ip y el user agent hayan cambiado, asi que la session FALLARA
//robar una cookie antigua tampoco ayudara, pues solo duran 15 minutos
session_start();
$id_usuario = $_SESSION['user_id'];
//busco en la tabla SESIONES si existe un numbre de usuario como ese
$query = "SELECT * FROM session_log WHERE id_usuario ='".$id_usuario."'";
//si existe, saco sus datos
if ($result = $mysqli->query($query)) {
while($row = mysqli_fetch_array($result)) {
$ip_check = $row['direccion_ip'];
$expirar = $row['expirar'];
$cliente_check = $row['version_cliente'];
$id_sesion = $row['id_sesion'];
}
}
//comprobamos que el usuario esta logeado, tiene buen user_agent, la misma direccion ip y no se ha pasado de tiempo
//COMPROBAR SI LA SESION HA EXPIRADO
$now = time();
if ($now > $expirar) {
$url = 'NO_SESSION.php';
echo '<script> window.location = "'.$url.'" </script>';
echo '<META HTTP-EQUIV=Refresh CONTENT="0; URL='.$url.'">';
}
//COMPROBAR QUE VIENE DE LA MISMA IP
if (isset($_SERVER)) {
if (isset($_SERVER["HTTP_X_FORWARDED_FOR"]) && ip2long($_SERVER["HTTP_X_FORWARDED_FOR"]) !== false) {
$ipadres = $_SERVER["HTTP_X_FORWARDED_FOR"];
} elseif (isset($_SERVER["HTTP_CLIENT_IP"]) && ip2long($_SERVER["HTTP_CLIENT_IP"]) !== false) {
$ipadres = $_SERVER["HTTP_CLIENT_IP"];
} else {
$ipadres = $_SERVER["REMOTE_ADDR"];
}
} else {
if (getenv('HTTP_X_FORWARDED_FOR') && ip2long(getenv('HTTP_X_FORWARDED_FOR')) !== false) {
$ipadres = getenv('HTTP_X_FORWARDED_FOR');
} elseif (getenv('HTTP_CLIENT_IP') && ip2long(getenv('HTTP_CLIENT_IP')) !== false) {
$ipadres = getenv('HTTP_CLIENT_IP');
} else {
$ipadres = getenv('REMOTE_ADDR');
}
}
if ($ip_check !== $ipadres){
$url = 'NO_SESSION.php';
echo '<script> window.location = "'.$url.'" </script>';
echo '<META HTTP-EQUIV=Refresh CONTENT="0; URL='.$url.'">';
}
//COMPROBAR QUE TIENE EL MISMO USER AGENT
$version_cliente = $_SERVER['HTTP_USER_AGENT'];
if ($cliente_check != $version_cliente){
$url = 'NO_SESSION.php';
echo '<script> window.location = "'.$url.'" </script>';
echo '<META HTTP-EQUIV=Refresh CONTENT="0; URL='.$url.'">';
}
//si ninguno de estos controles falla, llego hasta aqui
//significa que el usuario ha visitado una pagina nueva y sigue con la misma session, asi que debo
//actualizar el campo "expirar" para que la session dure mas
$new_expirar = time() + (15 * 60);
mysqli_query($mysqli, "UPDATE `wordpress`.`session_log` SET `expirar` = '".$new_expirar."' WHERE `session_log`.`id_sesion` =$id_sesion;");
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I would like to just have a single .pdf document that has all of my passwords and sensitive info included, but have it password protected so that I could store it in Dropbox and sync it to multiple computers/phones/etc. If I use the 256bit AES encryption with the latest version of acrobat, is this just as safe as password manager's technology? Is there any reason not to do this?
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A few years ago we had that awesome Linux distribution called Damn Vulnerable Linux.
But unfortunately it looks like the project is dead. So my question is are there other
Linux distributions which are meant to be hacked (explicit in the view of exploit development). Also welcome would be applications on the Windows platform for exploit exercises (like vulnerable server). Thanks in advance
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Lets first assume some things:
There exists an Adversary
There exists a known Group of Users of a certain System.
The User can communicate to the System through a small set of (to user and adversary) well-known Servers.
The Adversary wants to know if a certain User communicated with the System
The Adversary has a lot of resources and can see all incoming communications to the Servers of the System. (Assume some kind of tap)
The User of the System wants to mitigate the risk of an adversary seeing their communication and use a low-latency anonymity Network like Tor.
The whole communication between User and Server uses approximately 3 packets and uses TLS/SSL.
The Question is now: How likely can the Adversary mount an attack, where he uses some kind of correlation or timing attack to determine if an user communicated with the System. Assume the Adversary furthermore can either tap all Users communications or has control of many of many of the Autonomous Systems where the users traffic comes from.
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I was reading through the IETF's Public Key Pinning Extension for HTTP (https://datatracker.ietf.org/doc/html/draft-ietf-websec-key-pinning-12). The acknowledgements section has the following:
Thanks to Trevor Perrin for suggesting a mechanism to
affirmatively break Pins
Unfortunately, the link is broken in informative references.
Does anyone know anything about the break?
(Moderators: I had to tag this question with something to post it, and PKI was selected (but I realize its not a good choice). The questions should have been tagged similar to 'public-key', 'pin', 'pinning', 'pinset', 'ietf', 'rfc' or a few others. But none of the tags are available).
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My home network Edimax AR-7084gB ADSL modem/router with firmware verison 2.9.5.0(RUE0.C2A)3.5.18.0 was exploited from WAN few days ago. The attacker changed DNS server settings - primary server to 192.99.14.108 and secondary to 8.8.8.8. The first DNS server served a trojan virus (detected as Crypt3.NRM by AVG) via a fake Adobe Flash update page. My location is Czech Republic and media reported about the modem exploit with similar DNS settings so this was quite now common in my region.
I swapped the modem for a different one in the meantime (Siemens CL-040-I) which hopefully will not be compromised anytime soon. My question is what should I do in long term to prevent similar attack on the modem side? Sure I could set manual DNS server on all PCs but I dont want this because of administrative inconvenience. Will a common inexpensive brand new SOHO modem have a secure enough firmware to prevent most of the usual exploits? Are there any modem WAN security rankings that I could use then looking for new modem brand and model?
I updated firmware on the Edimax to version 2.11.38.0 (dated 2010-12-08, original version dated probably to 2007/2008) but I am not sure if that will be enough to prevent the exploits. Before the attack the modem had a custom weak password and with WAN administration disabled.
Edit: I realized that my WAN administration was enabled, because it is enabled in the factory settings (probably of all historical and current devices with Trendchip Front End since this Front End still ships with TP-Link or Edimax !!!) Such a factory settings is unbelievable... One has to explicitly forbid that in a custom Access Management setting. I guess most users won't do this after purchase anyways and thus reveal their login page into the public internet...
I also found the chipset type of the modem here (see "Specifikace"):
CPU: Trendchip TC3162P2
Front End: Trendchip TC3085 (web admin)
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I'm requesting some help with a particular breach of access that we've experienced in our environment. the attacker is an internal employee who has made a few notes about the environment that I simply do not understand clearly.
here are a few things he has claimed that I would like a little clarification on if someone would be kind enough to help me out.
1) "The router is accessible through this address - 0 x bdb38"
2) "memory tag (for transferring data) subnet is accessible through this address 0x00007fff78c6f2a8"
both of these comments have me a little stumped as they are written in short hand and I am unable to interpret them clearly.
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Are there known exploits where a query of the form:
select foo from bar where id = 6
can be turned into:
select * from select foo from bar where id = random stuff
It's clear that a badly formed app could easily allow injection
against the point in the query where the literal 6 is. I have
a case in hand where that was done, but also the extra
"select * from" was inserted at the front of the query at the
same time the literal at then end was attacked. I'm wondering
if this is either a generic known problem or if there are a class
of applications that are vulnerable in this way.
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I'm working on an implementation of Klein's wep attack.
For that, I've set up a router with wep encryption and collected 50,000 unique IVs from it.
I tried only calculating K[0], meaning - the first byte of the key.
I run on all my IVs and calculated the equation as the paper says while keeping a record of the number of times each calculated value was repeated. And finally I am printing the top 30 results.
My problem:
The correct first byte of the key is not in one of the first 30 results.
I keep getting negative numbers as keys.
Maybe there is something wrong with my calculation? Maybe I'm not understanding the algorithm properly?
I will put my code here if needed, but since the calculations are fairly simple, I think there is something else wrong.
I am using this as reference:
http://www.item.ntnu.no/_media/people/personalpages/phd/anton/kleins_and_ptw_attacks_on_wep.pdf
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No matter we are talking about Information Security, or cyber security or IT security... I always hear first about "the moth" being the first security threat. But I don't believe it is when talking about cyber security.
I believe that the infamous MARK II moth is a computer related incident, and it is even a security incident which affected the integrity of the code MARK II was running. But I don't think we can consider this a "cyber" security menace.
I have also read (and I am more inclined toward this thought) that, in fact, the famous "blue boxes" might be the real first cyber security incidents.
Others think that the first cyber security incident was the first virus ever in ARPANET: "The Creeper", but I believe this is more a concept application than a real menace, so, here is my question,
Which event is consider the first cyber security incident? and,
Is there any other than, due to its importance or relevance could be considered than the first real one?
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Lately (and not so lately), you can hear a lot about cyber security. It is really hard to find an official description about this matter so, let's take the ISO 27032 description:
"Cybersecurity” or “Cyberspace security”, defined as the “preservation
of confidentiality, integrity and availability of information in the
Cyberspace”. In turn “the Cyberspace” (complete with definite article)
is defined as “the complex environment resulting from the interaction
of people, software and services on the Internet by means of technology
devices and networks connected to it, which does not exist in any physical form”.
Further reading into ISO 27032 will discover some similarities with the ISO27001 and it is really hard to differentiate Information Security Controls from Cybersecurity Controls.
So my question is:
Is cyber security the "internet specific part" from IT Security?, are they just the same but now we call it this new way?
Or is Cybersecurity the new "IT Security" and now the old "IT Security" is part of this Cybersecurity?
Apart from the "technologies" or the "nature of the threats" is Cybersecurity bringing a brand new scenario to TIC Security? isn't it the same scenario but now we have more awareness of the same threats (or more people trying to explode the systems)?
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Can a website see my IMEI number? I have been banned from a website for multiple accounts, although I always cleared cookies, disconnected and reconnected from "the cloud" which gives me a different IP address every time. How do they know?
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I am just trying to get the basics of PKI and TLS and understand how it works. I came across Mozillas post about pkix where they mention that the new library allows graph processing and hence it handles cross-signed certificates, which is difficult via prior libraries since they use trees. This also removes the requirement of using AKI (authority key info).
Can anyone please elaborate what this means, what cross-signing is and details about AKI ?
Thanks
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Say I buy a prepaid sim-card with 3g data and put it in a used 3g modem (dongle) or a used smartphone and then create a Hotspot.
How would it technically be traced back to me? The ISP should see a Mac/IMEI of a device that isnt linked to me, and the IP is linked to an anonymous SIM-card.
Am I missing something here?
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I'm working at a company who is currently working to secure their mobile app (iOS native) by adding check points to security sensitive screens on the device (data is stored in the iOS keychain). User will be prompted to re-enter their password upon viewing these screens that present this data. One our requirements from Product team is asking for a usability feature that I think is a potential vulnerability.
They are basically asking for when the user leaves the field that they are typing their password to verify that it immediately turns to red or green, if the password locally is verified as invalid or valid. This seems it would make it too easy for an attacker to pick up someone's iPhone and repeatedly guess the password stored locally on the device. I would think we should check and validate with the server.
I'm asking for someone who may know more about the best practices to answer this question.
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There is a question bugging me a after reading on network security.
Theoretical situation: there is a packet-filtering firewall, which only accepts tcp/ip communication with destination port 22 on a protected private network.
(The port on a machine outside this protected network is not specified in the firewall's rules.)
Now imagine a botmaster, who tries to carry out an attack and communicate with a bot listening on port 80. The botmaster wants to for example send an IRC message "I got trough!" to any IRC channel, e.g. "starwars".
In order to get the packets trough (i.e. not get dropped by) the firewall, what kind of ipv4-packet should the bot master send in this particular scenario?
I'm especially interested in the TCP fields port numbers and the payload.
I'm totally confused on the 22 vs 80 part, how would that be possible. Why would this attack work?
And how could I adjust the firewall to be improved and detect any malicious behavior?
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Have a few thoughts on the topic, but the general gist is if a user inputs a new password, is it possible to have a high confidence that a password is not being reused elsewhere? By elsewhere, I mean on any systems not controlled by you.
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Scenario:
Alice prepares an URL link to Bob's web service (e.g., http://www.bob.com/sensitiveData/123?login=mallory).
Alice gives the URL link to Mallory.
Mallory follows the link to trigger an action in Bob's system.
Alice's link is intended for Mallory. Note that Mallory is authenticated by Alice but not by Bob. Bob does not know Mallory, but he trusts Alice. So if Alice has authorized Mallory to perform the action, Bob will blindly execute it.
The problem: How can Bob be sure that it is really Alice's link and that Mallory has not modified it in step 2?
In theory, such problems can be solved by a digital signature with a public-key algorithm. Alice could generate a signature of the link with her private key and append it to the URL, for example, http://www.bob.com/sensitiveData/123?login=mallory&signiture=<SOME-SIGNITURE>).
How do you generate the signature? As an experiment, I just tried gpg --encrypt but the results are quite huge. Additionally, it has to be encoded to use it inside an URL (e.g., with Base64), which will make it even larger.
As I'm not very experienced with cryptographic algorithms and protocols, I wanted to ask whether there is an well-known solution to the problem of generating signed URLs?
If not, do you see any flaw in my approach? Do you have any recommendation for the generation of the signature that can be appended to the link? If possible, it should be relatively short.
Just for clarification: Unfortunately, it is not possible to change the overall protocol. Of course, it would be safer if Alice and Bob could directly communicate over an encrypted connection. Additionally, Mallory should have to ask Alice to tell Bob to trigger the action, or Bob should have the option to ask Alice to authorize the action.
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Wondering if there's any research behind the most common password reset cycle I've seen of 90-days, and if there's any research that gives any insight into how to optimize password resets to reduce password reuse.
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Looking for research on the count and complexity of passwords that an average user is actively using.
Note: Also, just to be clear, by research, this is not a request for you to respond with an answer entirely based on opinions, rather than facts, references, or specific expertise. Likely the best answer would be based on analysis that is founded in statistically significant analysis on the topic.
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I'm trying to find all vulnerabilities in my given system.
Assume a malicious user has the executable (.exe file) of my .NET application (C#), and a malicious DLL he or she created. Can the DLL be injected into my executable to run code contained in the DLL?
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I've been developing web apps for quite some time now. While making websites, the "remember me" feature is one of the most trivial (read as must-have-for-clients) feature to be implemented. Until today, I was just using the default implementations provided by the ASP.NET authentication system - which I must say, is pretty secure (as long as one does not fiddle with the provided default implementation). But today, I just got curious about the implementation details of this feature. I did some research, and went through a few related articles:
Troy Hunt- How and how not to build
Troy's article basically comes down to the conclusion that, if possible you're better off not implementing this feature at all, as no matter what, despite your best efforts, you're always going to have to come down to a security-related compromise. Similarly, Barry's article, based on Miller, Charles design, he has some very nice strategic steps to minimize the attack surface and complicate the attack vector.
Why are the cookies not signed by the browsers? Wouldn't it be best if each browser-client (mobile/desktop/whatever), had their own unique GUID kind of thing, which was not to be modified (under any circumstances), and then they can send their GUID to the servers, and the server could then use as the key-value to decrypt/verify any client-side information (cookies/querystrings)?*
Wouldn't this solve the issue of session-hijacking/cookie-hijacking completely, as a cookie from one browser would then be totally useless for another browser?
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I'm studying the SSL/TLS protocol, more specifically its handshake. I know that initially, a client sends a Client Hello message to the server which includes the TLS version supported by the client.
I have an application that uses HTTPS connections, implemented with WinHTTP in the client and Apache Java in the server. I'm tracing the HTTPS traffic with Wireshark, which looks like this:
Client Hello, version-TLS 1.2
Server Hello, version-TLS 1.2
Client Key Exchange, version-TLS 1.2
Client Cipher spec, version-TLS 1.2
Application data, version-TLS 1.2
Encrypted alert version-TLS 1.2 [from client]
FIN version-TLS 1.2
ACK version-TLS 1.2
I don't know what Encrypted alert means (in Wireshark it is displayed as Encrypt alert (21)) - since it is sent by the client I'm assuming it's a Close notify alert.
A few seconds after the initial session is closed, a new session starts as follows:
Client Hello, version-TLS 1.0
Server Hello, version-TLS 1.0
Client Key Exchange, version-TLS 1.0
Client Cipher spec, version-TLS 1.0
Application data, version-TLS 1.0
Encrypted alert version-TLS 1.0 [from client]
FIN version-TLS 1.0
ACK version-TLS 1.0
From this, I conclude the version changes, and so the cipher.
This doesn't seem to happen every time: Sometimes a new session will use TLS 1.2, sometimes it falls back to TLS 1.0. What's the reason of this?
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If a certificate has a limited duration of, say 5 years, but it gets somehow compromised after 2 years, waiting the 3 remaining years for it to get invalid is not a real solution to the breach problem. (3 years is eternity in IT, I guess)
Also, if the encryption method gets cracked (à la WEP), you also need to update everything immediately.
What are the advantages to limit the validity in time (except for the issuer to make money on a regular basis, I mean)?
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I'm trying to understand what are the risks derived from unprotected communications within the same device, by the use of the loopback interface. I've verified it is possible to capture packets, with administrative privileges, on both Linux and Windows systems, by using Wireshark or RawCap/SocketSniffer tools. Would it be possible for some kind of malware to capture packets exchanges on the loopback interface in the same fashion, provided the malware obtains the needed privileges ?
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I'm seeing a lot of Content Security Policy (CSP) reports raised because of client-side malware. Many have "blocked-uri" entries like randomstring.cloudfront.net, something.akamaihd.net and so on.
I would like to detect CSP reports caused by malware, so I can ignore them. Ignoring *.cloudfront.net doesn't seem right, is there a way?
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I have been reading about oauth and 'how to create apis'.
In oauth2, there is what they call the authentication dance where the client will be requesting a request token using a consumer key and consumer secret. This request token will be used to acquire an access token. The expiring access tokens will be used for requests.
While in the "Step 3" of this article, they simply sign the data, send the encrypted data and the public key, and check it in the server side. similar to what oAuth1 does. Wherein they create a signature for each request
I am wondering why do they need to do all those "authentication dance" instead of just creating a signature in order to validate each requests.
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I've recently been introduced to Kali Linux's webkiller tool, located in the websploit category. It works on the concept of Tcpkill.
I don't understand how the DoS attack with Tcpkill works. Can someone explain it in detail?
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I am testing a website, basically mapping the site using burpsuite. But there is one link(https) that I can not process while the proxy on firefox is enabled. It asks me for certificates and when I ensure that I understand the risks and click on "add exception" the "confirm exception" icon doesnt seem to work,it just stays there. And Thus I can't seem to visit the link using burp.
I know it's a noobish question but the fact is that I am stuck here. Please guide me.
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I have the potential for a printer to be connected through USB and through a network cable at the same time. The USB would be connected directly to a computer which is part of a private network.
According to this: Attacking an office printer? Printers can definitely be used as an attack vector.
If the networks that the printer are completely isolated and can attacks be performed through a USB should the printer become compromised from the network connection? Is there a difference if the printer doesn't have a scanner (as the driver might have different permissions)?
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Can SSL encrypt the relative path I would like to visit in a site?
If I would like to make a login system with GET instead of POST, can SSL encrypt the part "?username=user1&password=pass1".
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We are next to launch an iOS app in App Store which is asking us for a privacy policy url as part of process when this app is being uploaded to app store.
We and most of our users are outside USA and our local privacy information regulations might not be equivalent to USA.One of the questions of our team is that under our local regulations geolocation is not sensitive information.If our app collects that kind of information from our users, are we forced to establish a privacy policy?
Is there any regional aspect we should take into account when we decide to establish a privacy policy for our application? Must we apply USA privacy regulations criteria to establish a privacy policy?
thank you
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While browsing PasteBin today, I noticed a new Paste that outlined approaches to compromising TrueCrypt protected data, as well as full Keys, Encryption Schemes, Plain-text Files, and Volume Names (and metadata). It was terribly un-nerving.
Appears this Pastebin was copied from this blog post, "TrueCrypt Master Key Extraction And Volume Identification."
My question is, what are the options to mitigate these attack vectors, barring Live-Boot/Read-Only OS's. Or are there any methods?
The Vectors outlined fall into two major categories:
Keys in Memory - Or keys left in swap-files.
Cached Data on Disk - Including data in swap-files, file history (some OS's cache files in plain-text), and TrueCrypt metadata (that can identify encryption schemes, volume use history, and identify the volume it's self [a USB drive with certain characteristics, or a specific file]).
Due to OS caching, my initial expectation is that there is no way to mitigate these attack vectors without a Read-Only OS, but I thought this was a good place to double-check.
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I'm researching XSS vulnerabilities in a web application which uses continuations.
That means that for a given form, the URI the form data is posted to is unique and different every time.
A first GET request displays the form with its unique URI such as:
http://test.local/webapp/4b69615449222508116a1e562e1e0a458e4d6351.continue
Then the submit action does the POST request.
Is there any free (or better open source) security scanner which understands continuations and is able to do the GET request before each POST request the fuzzer is trying to send ?
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Similar to how it can be easily done for RSA:
openssl req -x509 -nodes -newkey rsa:2048 -rand /dev/urandom -keyout example.key -out example.crt -days 365
I'd like to generate an ECDSA cert/key in one step. I've tried:
openssl req -x509 -nodes -newkey ec:secp384r1 -keyout ecdsa.pem -out mycert.crt -days 30
Returns the below error
Can't open parameter file secp384r1.
I am trying to specify the curve to use. If a key file exists, then you can specify it with ec:example-ecdsa.pem and it will work.
Possibly something like this could work with tweaking:
openssl req -new -x509 -nodes -newkey ec:$(openssl ecparam -name secp384r1) -keyout cert.key -out cert.crt -days 3650
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I received an email from my web host recently that informed me I had an "insecure" password on one of my email accounts and that I had to change it.
Their definition of what a secure password is as password that contains:
Mixed case - Always use a combination of uppercase and lowercase characters
Numbers - Always use a mixture of numbers and letters
Special Characters - At least one of the following special characters !"£$%^&*()-_=+{}#\@':;.>,<\|?
Length - Your password must be at least 8 characters long
Unique Characters - Your password must contain at least 4 unique characters
Whereas I follow the http://xkcd.com/936/ policy of a very long password (over 40 characters and 166bit of entropy (according to KeePass).
I am trying to think how they know what my password is (in order to tell me the digits it does not contain) without storing it in plain text.
The only "good" idea I have is that they have stored it encrypted and have decrypted it, analysed the plain text for "security", then deleted the plain text. But then I don't like that idea much given how easy it would be to decrypt if the site was compromised and the encryption key presumably also taken.
My other idea was that when I entered my password and before salting and hashing it, they gathered some statistics of the type of characters it contained. This seems unlikely and also a Bad Thing.
Any other ideas how they can do it?
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Lets say I can control the EIP CPU Register, and I want to jump to a specific function of which I know the correct memory address. This address is inside the same memory page. We have no exploit mitigations enabled. Can I then just pass the memory address of the function to jmp and load that into EIP?
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I was wondering what some of the potential abuses could be for an HTTP API that accepted SQL queries and output results sets. The fact that this is the canonical definition of SQL injection is not lost on me :)
In my case, I have a specific PHP/MySQL application in mind which is Magento - an eCommerce platform.
Here are a few security measures I've considered:
Non-standard URL route - to prevent mass scanning, each installation would have it's own URL route (this is similar to how Magento's admin backend is handled)
A decent length API key
HTTPS-only access
Read-only access via a read-only MySQL user.
Read-only access via SQL parsing. It would require a little less configuration if read-only access could be implemented this way. I was considering simply parsing the queries for "INSERT ", "UPDATE ", "DROP ", etc.
Blacklisted tables and fields. For the most part, configuration data is stored in a table called core_config_data, so that could be blacklisted. Also things like credit card tokens can be stored in a specific field of a specific table. In very poor implementations, credit cards can be stored in the clear as well, which would need to be blacklisted of course.
White list table and field access - Perhaps only allowing access to whitelisted tables and fields would be a better approach than a blacklist.
There are a lot of community extensions that could potentially store sensitive information as well. It would be hard to generically block them by default, so I think a whitelist might be the only option to solve for this.
Some mechanism for a maximum number / frequency of retries
Other standard things that are used to secure SSH connections for example, such as an IP whitelist, public key auth, VPN, etc.
Assuming that these measures were in place, would this be as secure or more secure than, let's say, SSH access locked down by an IP whitelist.
UPDATE: Few more specifics of the application, to follow up on some of the questions in the answers.
The thing that I'm looking to build is a Magento module that will get deployed to the store and accept SQL queries to return back data to my SaaS app. I own both the module and the SaaS app.
The application in question would be a SaaS app that tapped into Magento to pull data in. So it's not a situation where only trusted employees have access.
The ideal minimal level of security (from an amount-of-configuration perspective) would be to not use a read-only user.
Let's assume that the false positives that would be blocked are not an issue (Sorry, "Bobby Insert Tables").
UPDATE 2: Just wanted to flesh out a little bit more the reason why I chose to frame this question in terms of comparing it to an SSH connection with an IP address whitelist.
An SSH connection for all intents and purposes is already functionally the same as a raw SQL API (plus a whole lot more) in the sense that you can SSH in and connect to MySQl and then do whatever. So my thinking is that if a SQL API is as secure or more secure than an SSH connection, it may present an acceptable level of risk.
Also, I know this type of question can be overly subjective, so I wanted to frame it in a way that could have a relatively objective answer, which is why I wanted to compare it to a specific SSH scenario.
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In terms of PCI requirements and compliance, is a software-based key management module like Gazzang zTrustee an acceptable solution to the PCI requirements that a (hardware) HSM solution like AWS CloudHSM solves?
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A problem with many challenge-response login systems is that the server has to store a password equivalent. For example, if the server stores SHA1(salt + password), and an attacker captures that hash, then they would be able to directly use the hash to login, without having to crack the password.
I believe there are some variations of challenge-response login that avoid this weakness. In particular, I have heard that newer versions of MySQL have fixed it. I do not have any references or further information on this, but I would like to know how this can be done. I can imagine some approaches myself, but I would prefer to use a standard, peer-reviewed protocol.
I am aware that SRP solves this problem. However, SRP is more a public key protocol rather than challenge-response. I am particularly interested in protocols that only use symmetric ciphers, hashes, and maybe some XORing, etc.
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Is there a way to include my own attributes into an openssl certificate?
e.g
...
Country Name (2 letter code) [GB]:
State or Province Name (full name) [State]:
Locality Name (eg, city) [City]:
Organization Name (eg, company) [My Company Ltd]:
Organizational Unit Name (eg, section) [Section]:
Common Name (eg, your name or your server's hostname) []:
Extra Stuff (eg, dunno) []:
Extra Stuff2 (eg, dunno2) []:
.....
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We're building a public single page app in JavaScript that talks to a back-end REST service. What we want is for that REST-service to be only accessible from the single page app.
Since it's a public website, we can't / don't want the user to enter authentication details. Any normal authentication mechanism won't work either since any secrets stored in JS are legible to anyone.
I think it's impossible to secure the REST service, since it basically has to be public, but I was wondering if anyone has an idea how you would prevent someone from building a script and reproduce our application using our REST api.
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I'm wondering whether an HTTPS API endpoint would be as secure as or more secure than SSH.
API Endpoint
The API endpoint would require HTTPS
The API authentication would use a POST'd API key.
The minimum required length of the API key could basically be arbitrarily long
The API endpoint would only accept connections from whitelisted IP addresses.
The API endpoint's URL would not be publicly available or linked from anywhere. Only the client application would know what it was.
The client application connecting to the endpoint will not accept weak SSL cyphers.
SSH Connection
For the purposes of this question, we'll make the following assumptions about the SSH connection that we're comparing to.
The minimum required password length is 8 characters with upper case, lower case, and number required.
The domain that you connect to is the public facing domain (i.e. for http://domain.com you connect using ssh domain.com)
Considerations
Some considerations that I've thought of which may affect whether or not one is more secure than the other are:
Is HTTPS's detection of IP address as reliable as how SSH does it? I'm guessing both of them just look at what the client sends them and therefore can't be 100% trusted, but nevertheless provide some level of security.
I believe that SSH has a built in mechanism to prevent rapid retry attempts. I know that HTTPS by itself doesn't do that, but in many cases where security is paramount that it built into the web serve layer.
My hunch
My hunch would be that the API endpoint would actually be more secure than SSH for the following reasons - but I'm not a security expert by any stretch, so I'd love to get a solid answer:
With SSH, the potential attacker knows what domain to target (i.e. ssh domain.com). But with the API, the URL would not be known so in order to even begin to try to attack it, they'd first have to figure out what the URL was.
The API password strength is greater
Context
The reason I'm asking this is that I'm considering building an API endpoint that would allow a trusted, authenticated user to access a lot of potentially sensitive data. It would be a powerful tool that would allow for nicely decoupled application business logic to be written very quickly.
The reason why I'm asking whether it's as secure as SSH is because my assumption is that potential users for this application have SSH enabled with at most an IP address whitelist as an additional layer of security.
So that is to say that the capabilities of this API endpoint are already present via SSH. If the endpoint would present no additional risk over and above the risk that is present with SSH, then I would consider that an acceptable level of risk. But if it were less secure, then I would most likely not consider it acceptable.
UPDATE: Added note about weak cyphers to API endpoint.
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Some services like Github has DDOS mitigation measures for their root/naked domain, but not other subdomain(s).
What so special about the root domain concerning the DDOS attacks?
[1] http://instantclick.io/github-pages-and-apex-domains
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Last week I was told by our security department that my PC (running windows 7) was infected by a trojan and that it needed to be re-imaged. So re-imaged it was! Given the fact that I had been using this PC for a while, visited thousands of web pages and used USB key to
3 days later, the security department notified me again that my PC is infected with malware and that my PC will (again) need to be re-imaged. Since I do not want to reimage my PC every 3 days, I want to figure out the infection vector (assuming it is the same malware)
Possible infection vectors I found:
Visiting a compromised web site
Downloading a trojan hidden in legitimate software (I did not download/install more that 3 pieces of software since the reimaging,
so that should be easy to find)
Connecting my iPhone to the USB port of my computer to charge it.
Can the latter be the cause of infection, even if the drive was not mounted? If so, is there a way to check/disinfect it?I found lots of tools for autorun.inf related malware, but these require the media to be mounted as a drive.
Edit: I have not been told what the exact malware was, nor when or how it was detected.
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I am thinking about an anonimity network (just as tor), but using some type of guarantee against mis-usage. For example, which torrent does: there is a tracker, which registers who has given how much how many pieces of a file, and uses this data to help or stop the actual downloader.
I am thinking about the same thing, but not with file pieces, but with network bandwidth.
Thus, you could get for example 1 gigabyte anonimized network traffic - but only if you give 1 giga for other somebody.
Does this, or something such this exist already?
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I am thinking on a system, which measures the complexity of a password not based on its entropy or compressibility, but with a simply sophisticated method.
The measurement of the entropy/compressibility are measuring the idea, "how hard is to build this password from bytes". I am thinking on a method, which measures "how hard could this password be build from the concepts in the mind of the crackers".
What are in the mind of the crackers? Words, and algorithms. Thus, what need to be find out: how hard is it to build from the word and algorithms living in the mind of an intelligent entity whose goal is to crack the password. They use vocabulary of course, also these words should be also viewed.
Are there some mathematical model using this concept?
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If I connect to an evil twin wi-fi hotspot, aka rogue AP, among other names, are only the data being transmitted at risk, or, are the data on my HD also vulnerable?
I am working with Windows 8, updated.
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Please excuse my probably gross misunderstanding of how all this works.
I just started reading SSL & TLS Essentials by Stephen Thomas, and in chapter 1 he talks about how TLS is a separate protocol layer below the HTTP application protocol, and since it is a separate layer, different application protocols may use it (such as FTP).
My question then is if wireless devices use HTTP (they do right?), why do we need a separate protocol for WTLS? Why can't regular TLS be used for wireless devices using HTTP just as it can with wired devices using HTTP?
According to Wikipedia, WTLS is part of the Wireless Application Protocol (WAP) stack, but again if TLS can be used in conjunction with multiple application protocols, why couldn't TLS be used with WAP?
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I'm playing around with Snort's downloadable rules and I found one which is easy to activate: sending a unicast ARP request. Okay, so I start injecting ARP requests, making sure the destination is not set to broadcast. And sure enough, Snort picks it up. Great, let's move on and do more complex stuff.
Though, I'm not sure I understand why this rule exists at all. From what I've read most ARP spoofing/cache poisonning attacks make use of ARP replies; requests do not seem to cause anyone any trouble (here ("What can be done", paragraph 5) for example, unicast "keep-alive" requests are even said to be a problem when implementing attacks).
Yet this rule exists, and I cannot find any justification. Why is it suspicious for an ARP request to be unicast, when apparently in a lot of implementations this is considered a feature? There's a book on intrusion detection focusing on Snort that says "ARP requests that are sent to a Unicast address are often the sign of an attack designed to modify ARP caches". I... can't see how?
Then again, I don't have much experience with network security so I guess I'm not thinking creatively enough.
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Considering that I have a structure like the following, allowing only the TCP and UDP ports for SQL to be accessed. Specifically no traffic initiated from SQL is allowed to reach SECURE.
SECURE-> SQL <- STANDARD
|-> SECURE-SQL
What kind of attacks are there out there to compromise SECURE - and therefore eventually SECURE-SQL - , assuming that the server SQL is compromised? I've read about a lot of attacks, but not anything really covering jumping from SQL to a web server when you don't have direct network access.
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I've looked on this site and on SE. but I couldn't get a handle on this. Is there a way to find what type of encoding (and/or encode key) is being used? For example, I am testing a web application(PHP) which will encode the links before it will be showed to the end-user.
For example, the source link is:
https://www.amazon.com/gp/drive/share?s=OUhODh-US9cj1EVKlakRWw
Then the encoded output the link will be:
Wkt6OVpIeHBLR0J1Umx6TkdVRWRlZm03MExydXhnTTI4UEUvTGN1YkM1VW5Ma2JkQUJ4T3hMNDNhWjREZ3ZoNlUyd1lETmRoRlZlRFZlRVdNVzY0OGc9PQ==
Is there a way to find out which encode method was used and the passkey (the string that was used to mix/replace the input string to produce the output string).
Aside from just trying a bunch of common hashing/encoding sequences on the original strings and hoping to stumble across a matching output? If I have a lot of input strings and output hashes does that help in any way for analysis?
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Traditional situation
It is easy to crack a ciphertext encrypted by Vigenere cipher, if you know the plaintext is in a natural language like English. There are two methods to discover the key used to encrypt the plaintext. Either you know frequencies of certain characters that will occur more often than others (e for English) or you know a word that will occur in the plaintext (the, a, etc. for English).
Cryptographically secure random
What if the plaintext is actually CSR (cryptographically secure random) data, and you encrypt it using Vigenere cipher with a CSR key.
Let's say we reuse the key four times (to account for flaws if random is not CSR?). Also, the key is sufficiently large so that brute forcing it is not an option (for example, the key may be 1KB, and therefore the cipher and plaintext is 4KB).
Would it be possible to crack that, even though you are reusing the same key (the key is also CSR) but not as large as the plaintext data?
or: how secure is this relative to other methods for encryption/decryption?
Context
In case you ask yourself: 'why would you want to encrypt random data?':
Well, if the answer is no, and thus it is impossible to crack it. That would mean that once a shared secret is established between two persons, you could establish an information-theoretically secure connection, right? Because once you have a shared secret key 'A' of 1KB. Then you could create a shared secret key 'B' of 2KB using 'A' two times on newly random generated data. Then you could use 1KB of 'B' as a one-time pad on your actual plaintext communications in English. And you could use the other 1KB of 'B' for safely communicating the next 2KB sized key and so forth.
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I am trying to do a Snort demo and I though it would be nice to detect a real threat. I picked the sasser worm and the jolt/teardrop dos attacks for the demo; no particular reason.
Out of the three only one, the teardrop attack, is detected.
I have tested snort with "testing rules" (alert every tcp packet, search for a string in the payload, ...) and they seem to work flawlessly. I checked Snort output and there is no warnings nor errors for the files containing the rules for sasser/jolt.
I have not much experience writing Snort rules so I picked them from recognized security sites and github.
Sasser traffic is generated by the sasser worm, which I found online and compiled. Jolt and teardrop traffic is generated with the tool targa2.
I checked the traffic with tcpdump and it seems to be OK. Sasser generates traffic directed to the windows update port and both jolt and teardrop generate ICMP packets.
Having tested all the previous I guess the problem are my Snort rules. I've beem intesively Googling but I found nothing new so it would be nice if someone could check if these rules do what intended.
Here are my sasser rules:
alert tcp $EXTERNAL_NET any -> $HOME_NET 445 (msg:"NETBIOS SMB-DS DCERPC LSASS DsRolerUpgradeDownlevelServer exploit attempt" ; flow:to_server,established; flowbits:isset,netbios.lsass.bind.attempt; content:"|FF|SMB"; depth:4; offset:4; nocase:; content:"|05|"; distance:59; content:"|00|"; within:1; distance:1; content:"|09 00|"; within:2; distance:19; reference:cve,CAN-2003-0533; reference:url,www.microsoft.com/technet/security/bulletin/MS04-011.mspx; classtype:attempted-admin; sid:2514; rev:5;)
alert tcp $EXTERNAL_NET any -> $HOME_NET 445 ( sid: 1000041; rev: 1; msg: "LSLass MS-0411 exploit"; flow: established,to_server; content:"|eb10 5a4a 33c9 66b9 7d01 8034 0a99 e2fa eb05 e8eb ffff|"; reference:url,www.secuser.com/alertes/2004/sasser.htm; classtype: shellcode-detect;)
alert tcp $HOME_NET any -> $EXTERNAL_NET 9996 ( sid: 1000042; rev: 3; msg:"Sasser ftp script to transfer up.exe"; content:"|5F75702E657865|"; depth:250; flags:A+; reference:url,www.secuser.com/alertes/2004/sasser.htm; classtype: misc-activity;)
alert tcp $EXTERNAL_NET any -> $HOME_NET 5554 ( sid: 1000043; rev: 1; msg:"Sasser binary transfer get up.exe"; content:"|5F75702E657865|"; depth:250; flags:A+; reference:url,www.secuser.com/alertes/2004/sasser.htm; classtype: misc-activity;)
Here my Jolt rule:
alert ip $EXTERNAL_NET any -> $HOME_NET any (msg:"DOS Jolt attack"; dsize:408; fragbits:M; reference:cve,1999-0345; classtype:attempted-dos; sid:268; rev:4;)
And finally the Teardrop rule, the only one that works:
alert udp $EXTERNAL_NET any -> $HOME_NET any (msg:"DOS Teardrop attack"; fragbits:M; id:242; reference:bugtraq,124; reference:cve,1999-0015; reference:nessus,10279; reference:url,www.cert.org/advisories/CA-1997-28.html; classtype:attempted-dos; sid:270; rev:6;)
Thanks in advance.
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According to the documentation a hidden volume stays hidden because it appears as free space. In TrueCrypt free space always has random data in it, however in the case of a hidden volume it's not actually random data but the hidden volume. I was wondering how is it possible to write (for example add a new file) to the outer volume with out risking overwriting the hidden volume?
As of TrueCrypt 4.0, it is possible to write data to an outer volume
without risking that a hidden volume within it will get damaged
(overwritten).
When mounting an outer volume, the user can enter two passwords: One
for the outer volume, and the other for a hidden volume within it,
which he wants to protect. In this mode, TrueCrypt does not actually
mount the hidden volume. It only decrypts its header and retrieves
information about the size of the hidden volume (from the decrypted
header). Then, the outer volume is mounted and any attempt to save
data to the area of the hidden volume will be rejected (until the
outer volume is dismounted).
Wouldn't this make it easy for an attacker to learn there is a hidden volume? As soon as he can't write to free space he'd know.
For example if an outer volume is created of 5 GB and an inner volume is created with 4 GB. An advisory forces the owner to reveal the password but is given the decoy password to the outer volume. Then the attacker wouldn't be able to write more than 1 GB (at the most) before seeing that there's a hidden volume.
Do I understand this correct? Is this a concern or is there a safeguard against this? Does it help to make the outer volume large so the chances of writing to the free space with the inner volume are low. If one was going to store a virtual machine in a hidden volume, that would take up quite a bit of space. It would be quite consuming to double this size by giving lots of room to the outer volume.
Also, what kind of "fake" sensitive files should go in the outer volume? If you think about it, it's not that easy to make fake confidential looking documents. You wouldn't be able to store any online passwords because they could be verifies as false easily.
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I'm setting up a Tor-based isolating proxy using the 'Anonymizing Middlebox' iptables rules specified here: https://trac.torproject.org/projects/tor/wiki/doc/TransparentProxy
i.e.
iptables -t nat -A PREROUTING -i $INT_IF -p udp --dport 53 -j REDIRECT --to-ports 53
iptables -t nat -A PREROUTING -i $INT_IF -p tcp --syn -j REDIRECT --to-ports 9040
...where 9040 is the Tor TransPort. The INPUT, OUTPUT and FORWARD chains are left at the default. Would there be any merit to also including the following rules?
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT DROP
iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
Or are they rendered unnecessary by my current setup?
Are there any other firewall rules that I should consider in order to improve security and ensure that all traffic is torified?
Many thanks.
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While reading up on iptables, I saw this article from NixCraft recommending that a server block the following bad addresses:
0.0.0.0/8
10.0.0.0/8
127.0.0.0/8
172.16.0.0/12
192.168.0.0/16
224.0.0.0/3
It doesn't say whether it is applicable for UDP, TCP or all traffic. My web server has an application running on TCP 127.0.0.1. I am more worried about spoofed source IP addresses like 0.0.0.0 or 127.0.0.1 reaching my server on TCP.
Seriously, is that possible at all?
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In a study project i have to plan a network for a small company (around 50 employees) and i am currently at the point, where i want to design the database architecture.
I read that its common to have a web server in the DMZ. The company has got an online shop. So it is necessary to access a database. Customers can create accounts and so on via the online shop. Where to put this database? Also inside the DMZ or inside the company's intranet?
Does it make sense to build up multiple DMZs, for preventing attacks on neighbor components in the DMZ? How to mirror customer data into the companys intranet?
Thanks for explanation!
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UPDATE: The source of this problem has thankfully turned out to be a buggy mobile SSH client used on 2 different devices not a MITM attack. However, I'd still appreciate a full answer to the original question: Namely, in the event of a genuine MITM attack, what steps should an administrator take after detecting it? Does the presence of a genuine MITM attacker effectively make SSH access to that server impossible for as long as they attempt to intercept traffic? Is changing the sshd port sufficient as a response?
ORIGINAL QUESTION:
I'd appreciate some advice on what steps I should take in dealing with this.
On attempting to connect to my home server today over SSH using pub key auth (password access is disabled), I received the 'fingerprint has changed' message. As I have a copy of the server's public key fingerprint on me, I can see they don't match.
Does this mean I am unable to connect to the server over SSH indefinitely without jeopardising security? Can I combat the attack in any way? While I've always been aware of the potential for SSH MITM attacks, and there is plenty of reading available on detecting such an attack, I cannot find any advice on countering / dealing with it once it's underway.
Thank you in advance.
UPDATE: The SSH host's public key and the copy I have are identical. But when connecting remotely (using either DDNS or direct IP), the 'Authenticity of host can't be established' message shows a different fingerprint to the server's. I need advice on how I connect to the server via SSH from now on in light of somebody potentially doing something nefarious. Do I simply change the SSH server port? Should I generate new keys?
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I have a free ssl certificate issued just before Heartbleed was found. Now my CA wants me to pay 25$ to revoke it.
Should I pay or it's just enough to create a new certificate from another CA an replace existing?
Considering there are no real users of my site (the site is still in development and nobody has my old certificate installed in his browser yet)?
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Visiting this site: http://ruby-doc.org/
I get this message:
There were 3 Ruby vulnerability reports in the last 14 days. 2 high, 1 medium. Most recent: CVE-2013-4562. See details.
I only installed ruby for fun and to play with it. Does this vulnerability affect me? I'm really afraid what should I do?
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Do you know if AVs scans non-persistent memory mapped file content in a Windows Environment ? (Or have the answers for some of the AV on the market) I would prefer, if possible, some real world testing or white paper, more than commercial speech from the AV developer.
ALso, do you know where I can find recent documentation about the in depth behaviour of MMF ? The one I have and the most complete is from 93', and since then I imagine some KB have updated some sec. holes in them.
Thanks in advance, I really can't find a lot of things ! :(
If not... will have to test myself :)
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I have a server which has 'loose' physical security (somewhat easy for the entire server to get stolen).
For the sake of the question, let's assume that anyone can access the server physically, what precautions should I be using to keep the data secure?
My initial thought would be to keep all logs, databases, user content, etc. in an encrypted TrueCrypt container. This means that if the hard disk/server is stolen, they will be unable to access the private data. However, what if someone plugs a screen and keyboard into the server? If I am currently logged in via SSH, does that leave the server vulnerable locally? Can I trust Linux's standard "enter password" prompt or can that easily be bypassed?
I'd like to be able to boot and access my server remotely without being forced to enter a password locally (for example if the OS was encrypted)
Thanks for your help
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Could a hash function like sha1 or ripemd-160 be used for secure key generation in a stream/block cipher? Obviously a repeated key like "abc123abc123abc123" would be bad, and a one time key pad would be impractical for large data... but what if one used a hash function to derive new keys from the origional password like:
DUMMY CODE:
$password = "secure password here!";
$round =0;
while(true){
$key = sha1($password . $round);
$data = READ 40 BYTES OF DATA HERE
$result .= XOR($data,$key);
$round++;
}
Not that i am going to use this for anything, but just curious, what would be secure/insecure about this method... thanks...
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Given that I have
an initial input that is publicly known (e.g. "ABCDEFGHIJ")
a slight variation of (1) (e.g. "BACDEFGHIJ") that is used as the input to a hashing algorithm (3)
an modern one-way hashing algorithm like BCrypt, Scrypt etc.
the result hash of (2) applied to (3). The hash is also publicly known.
How easy is to infer (2) given that (1), (3), (4) are publicly known and also that its publicly known that the difference between (1) and (2) are only minute. Say both inputs are 256 bytes long and only 2 bytes are swapped in their position.
Edit
I try to rephrase it. Given two hash function applications and 2 input values
h(b) = r1
h(a) = r2
where "h" is a publicly known one-way-hash-algorithm
where "a" is the input to h and its publicly known
where "r1" is the publicly known hash result
where "r2" can be easily calculated as "a" is known and "h" is known
where "a" is known to be very similar to "b"
Is there any function/process/method to infer "b"
f(a, h, r1, r2) = b
The answers I would hope for are
[ ] there is now way to infer b from a, h, r1, r2 as all one-way-hashes have
enough entropy (I hope this is the right term) even if the input values
are almost identical
[ ] given enough hash results and enough input values which are known to be
slight variations of the real input values one could use these (...) and
these (...) attacks to calculate the initial input values
[ ] Yes there are known attack vectors under this circumstances, however it
will need a quantum computer of the size of a NSA cluster to break it
[ ] given that a, h, r1 and r2 are known its a matter of a few minutes to
infer b by using the following attach vectors (...)
|
Reviewing openssl 1.0.1g s23_clnt.c code i see that :
int ssl23_connect(SSL *s)
{
BUF_MEM *buf=NULL;
unsigned long Time=(unsigned long)time(NULL);
void (*cb)(const SSL *ssl,int type,int val)=NULL;
int ret= -1;
int new_state,state;
RAND_add(&Time,sizeof(Time),0);
This RAND_add(&Time,sizeof(Time),0) will not add entropy, but does it on the long run just create a predictable random ?
Reading https://www.openssl.org/docs/crypto/RAND_add.html there is a line "Thus, if the data at buf are unpredictable to an adversary, this increases the uncertainty about the state..." , what if buf is predictable... because time of initial connection is.
Since default random method is md_rand, i think buffer is added even if entropy is 0 and i think adding easily guessable information ( time is in seconds ) will dilute and on the long run make week random
Googling a little gave that https://www.schneier.com/blog/archives/2013/09/conspiracy_theo_1.html#c1694020 that just gives me same impression, but i really doubt such things would not have been kept for ages in openssl ( it was already there with a RAND_Seed(&Time, ... in SSLEAY of 1998 ) if it was so harmful.
So a basic question :
Does RAND_add(X,Y,0) with X guessable lower the random quality or keep it as it is ?
|
All questions ask about the other way round, ie. can a virtual machine compromise the host. But I'm asking can a virus on the host machine compromise the guest virtual machine?
|
Would anyone be so kind so as to describe to me the Serpent-256 cipher? How does it work and how secure is it compared to AES?
I have searched everywhere and found scarse info about it.
Anything related to it (speed, security, mode of operation, programs which use it, etc.) are highly appreciated.
|
As I am working on a research, I need allow users to read my JavaScript file using Ajax. However, I want to make sure about consequences of adding Access-Control-Allow-Origin header for just this file.
Access-Control-Allow-Origin: *
I know about the goal of origin control and all examples about accessing behalf of user. However, enabling this feature for just one static JS file can cause any security problem?
Any help is appreciated.
|
I administer an Ubuntu Server 14.04 which acts as a mail server running Postfix and was configured following most parts of this tutorial: http://www.pixelinx.com/2013/09/creating-a-mail-server-on-ubuntu-postfix-courier-ssltls-spamassassin-clamav-amavis/
I have ports 25 and 143 open to the public use STARTSSL communication for both in and out and can connect using IMAP from the outside without problems.
I have fail2ban enabled (and actually bans IPs quite frequently) and also have configured some parameters to prevent spam:
smtpd_helo_required = yes
smtpd_delay_reject = yes
disable_vrfy_command = yes
smtpd_sender_restrictions = permit_sasl_authenticated, permit_mynetworks, reject_unauth_destination
smtpd_relay_restrictions = permit_sasl_authenticated, permit_mynetworks, reject_unauth_destination
The question is that from a couple of months ago, I see this trace in the mail.log every few hours:
Apr 23 05:52:08 myhost postfix/smtpd[9727]: NOQUEUE: reject: RCPT from 118-165-146-33.dynamic.hinet.net[118.165.146.33]: 554 5.7.1 <gk49fawn@yahoo.com.tw>: Relay access denied; from=<z2007tw@yahoo.com.tw> to=<gk49fawn@yahoo.com.tw> proto=SMTP helo=<xxx.xxx.xxx.xxx>
IP addresses change regularly, and recipients also do change from time to time, but the sender is always the same. Also, since it appears only a couple of times a day, fail2ban does not react against it.
I understand that the relay is being denied properly so it is not a big deal, but should I worry about this and/or take any extra action against it?
|
I want to understand how a vulnerable internet facing process on some computer is exploited to run arbitrary binary code.
I understand how buffer overflows could be used to overwrite the return address to make the process jump to a location it wasn't supposed to - but I don't know how it's possible for a process to execute arbitrary binary code that it recieves from an attacker.
It seems like if an attacker sends binary code to a process it will never be put into the .text section so it will remain non-executable, even if 'return' jumps into it. Stack and heap overflows wouldn't write into the section where code is stored, so they will still have a no execute bit.
Edit: To be clearer the main part I don't understand is this:
the .text section where binary assembled CPU instructions are stored cannot be modified
the .data/.bss section is marked as no-execute so that the information there will only be treated as data, will never be executed by the CPU
|
I have identified a stored XSS and I'm wondering, how could I leverage that vulnerability to upload a shell.
|
There's a file processing service that looks for some know attacks and sometimes returns messages like:
Probably harmless! There are strong indicators suggesting that this
file is safe to use.
Are there heuristics that model the likelihood that a file is harmless, and if so, what is a simple example of such a heuristic, and what is the best way to learn more about the topic in general?
|
I am writing a service-oriented (REST) application that is (nearly) totally stateless: it can authenticate by API keys, but for web UI it uses the session where it stores nothing but an authenticated user's ID (int). Session ID is generated randomly as it's usual to see, user ID's are never exposed to the users as users are always referenced by their username
Here's the idea I got. What if instead of assigning random session ID I would generate it in the following fashion:
N1 random bytes not including flag byte + flag byte + user ID + flag byte + N2 random bytes;
or in other words, N random bytes containing a scannable ID somewhere within, all encrypted with server's secret key. It's also possible to use client's IP as a part of the string or as IV, to mitigate session hijacking.
The benefit of this approach is that the need of session is completely eliminated, and for scalability matters it's only required that all nodes use the same secret key (session replication is not required either). With regard to performance I'm not sure whether in-memory decryption (let's say, 128-bit AES) would be faster or slower than reading session data from disk and pruning it time to time. The only attack vector I can think of is attacker creating two accounts in a row (so that ID's are sequential) and bruteforcing their two session ID's to obtain the secret key (which, I believe, would not be feasible if it is effectively long).
What I want to ask is:
What do you think about security of such approach? (I'm concerned since the only recommendations I have seen so far is "use strong random for session ID's", and never read about such encrypted session ID approach — but that might be just people really loving to use session to store data there);
What are the possible ways of cryptoanalysis beyond the described one?
What are the downsides, beyond possibly long session ID?
Is it a known approach (then where is it documented?)
|
My friend just posted a picture of her key to instagram and it occurred to me that with such a high res photo, the dimensions of the key could easily be worked out.
Therefore the key could be duplicated.
What's to stop someone malicious from abusing this?
|
I would like to move from sequential to random user IDs, so I can host profile photos publicly, i.e. example.com/profilepics/asdf-1234-zxcv-7890.jpg.
How long must user IDs be to keep anyone from finding any user photos for which they have not been given the link?
Does 16 lowercase letters and zero through nine provide a reasonable complexity? I'm basing this on 3616 = 8x1024, conservatively estimate 10 billion user accounts reduces the space to 8x1014. At 1000 guesses/second, it would take 25 000 years to find an account. Unless I'm overlooking something.
|
I may have to visit family in a few months overseas. Unfortunately, the local government of the area my family is from has gotten more corrupt and vicious. I am compelled to go here and may need to use Internet while I am with my family, and I heard of creating live USB.
https://fedoraproject.org/wiki/How_to_create_and_use_Live_USB
Unfortunately, I cannot find how to create live USB that will protect my identity (hide my IP address, location, etc) once I am in that foreign country. I know it can be done, but I am unable to find these resource on the Internet now.
Any guidance is greatly appreciated.
|
I have two ubuntu laptops that were recently compromised. I understand that it's probably a fruitless endeavor to try to find the hacker. I want to know how to secure my ubuntu desktop so that the hacker is kept out in the future. I'd also like to know how to secure my computer against a man in the middle attack on ubuntu and windows.
|
Recently I Googled the email address of one of my friends, as I was just curious of what would come up.
Lo and behold, he saw what presumably is his Gmail hash.
It is part of a list of 10,170 email addresses and hashes. First of all, I was kind of surprised that Google, of all things, would be compromised (or is it?). Phishing?
He reported a few weeks ago that his email account had been sending strange emails. Something bad is obviously going on. What should he do?
|
I am developing a program that I want people to be able to connect to and use via ssh.
I've decided a simple way of doing this would be to create an account for them on my linux server, and change which shell they use to login, to be my program instead of bash.
One measure I can take is to remove their PATH variable so that if they do somehow get access to bash, they won't be able to run any commands.
Is this horribly insecure? Am I replicating some other existing thing? Perhaps I should simply implement an SSL connection instead of SSH?
|
I have this silly question that is bothering me. When not using secure connection (HTTP for example) cookies can be intercepted and used to connect to the site as if we have the id and password. We can protect against this by using secure connection (https). This assures that the cookies sent to the server are encrypted.
My question is: why can't an attacker use the encrypted cookies? Could an attacker intercept these cookies and send them to the server?
|
I'm not sure if this is the right place to ask this question. Please tell me, and I'll delete it.
I want to modify a Word document hosted on my OneDrive account. I see that it is using a SSL connection with a valid certificate (https://).
I'm asking, if there is a proxy on my network (I think, there isn't), and I read an encrypted Microsoft Word document, could anyone read it on my browser cache or on that hypothetical proxy?
|
A German hacker famously managed to brute force crack a 160 bit SHA1 hash with passwords between 1 to 6 digits in 49 minutes.
Now keeping everything constant (hardware, cracking technique - here brute-force, password length etc.) let's say it takes 1 hour to crack a SHA2-256 bit algorithm (the time taken is just an example, I know that's not the case currently) then how do we estimate the time taken to crack the SHA-512 hash or the SHA2-384 or SHA2-224 hashes?
The hash type is also an example, an other way of asking this question is if it takes 1 hour to crack a hash of 128 bits, how do we arrive at a formula to estimate time to crack the same hash type but of a different bit strength, everything else staying constant?
|
I have many applications installed on my server that use a webui frontend to control the application.
Since I am the only user of the server, I usually bind these applications to 127.0.0.1.
As the services are bound to localhost, I have assumed that I can disable authentication (usually username+password), for these applications, because nobody outside of my local machine can even access the services.
I access the services by using an SSH tunnel; so essentially it gives me access to the server's local services from any machine.
An example: I installed BitTorrent Sync. The app uses a webui that I bind to 127.0.0.1. I then disable username+password auth for this webui, and access it using an SSH tunnel from my remote location.
My question is, is this secure?
Would it be better practice to enable the application's authentication scheme? (I assume not, since it is bound localhost).
Is it possible for an attacker to somehow spoof 127.0.0.1 and get access?
|
If I'm right the SSL encryption take place in the application layer, but we can also have encryption in the Internet Layer.
Why are we using both, and why sites that doesn't have SSL are considered insecure even tho the information is encrypted in the Internet Layer anyway.
Also is it possible for anyone in the Internet to sniff packets of a site (ex. stackexchange.com) or the attacker should tap the cables outside of the building the servers are located.
And if we have encryption in the Internet Layer and Wi-Fi is physical layer why is it considered insecure to log in to a site without SSL in a public Wi-Fi network.
|
I've got a Kali Linux box I use for pen testing.
I would like to configure my machine to DROP incoming packets, but only when I'm not listening on them.
e.g. if I run a netcat listener on port 80, I would like connections from the internet to be possible, but as soon as I stop netcat I would like the packets to be dropped rather than rejected.
I know this would be possible by the use of scripts, but is there any support for iptables to do this automatically?
I have had a suggestion to use the NFQUEUE target for all incoming packets, but then I'll have to modify the source of the listening application (if no user-space application is listening on the specified queue, the packets are dropped).
|
I have a webserver in my windows machine running Apache(XAMPP).
I have created an Android application that connect to my webserver at localhost.
How can I capture the data with wireshark on localhost?
|
A while back I enabled SMTP on my IIS server with the intention of using it for internal email notifications. It seems that somehow hackers were able to use it for sending out thousands of spam messages.
We've corrected the issue by adding some authentication to the server, but we're no longer trusted by many email clients. I'm guessing they must just assume we're still sending out spam by our IP?
Will our "stigma" ever go away so that we may send emails that don't go straight to the spam box? IP addresses are recycled so I don't imagine we can just be blocked forever.
|
I was thinking whether or not you can find the hash function(s) used if you have the original message and the hash. So assume that no salt is used during the hashing process, just multiple hashing and concatenation, e.g.
hash = SHA512(MD5(original) || SHA512(original))
So how could you find the right hashing process, if really no salt is used and the process does not depend on other things like system time etc.? Remember that the original and the hash are given. Is the only way to find the right hashing sequence brute force?
|
The situation is: a hall full of 200-300 people, one of them is performing an arp-cache poisioning attack. Or messing with my network over wifi in any way.
Is there a way how to determine the location of him? Using some kind of directional antenna or something? I dont need to be very accurate, when I have the direction, I will probably find the suspicious one.
I know that this is almost impossible, but if anyone know something to suggest and try, I would really appriciated that.
Thanks for any ideas.
|
Control Panel says it's 192.168.1.1; Google, whatismyipaddress.com etc. says it's 75.92.141.32
When I put the IP address reported online in my address bar I get a Nokia login page, but my ISP is Clear. I think someone may be trying to hack my computer or something.
|
I set up a CA and signed some cert request.
I revoke them by:
openssl ca -config config.cnf -revoke cert.pem
I update CRL by:
openssl ca -config config.cnf -gencrl -out crl/crl.pem
index.txt shows a 'R' for this cert, also when I check the crl.pem the cert is listed as revoked. So I think that worked fine.
Now the issue: I can not check the cert if its revoked. Can some give me the right command.
If I try:
openssl cerify -CAfile cacert.pem cert.pem
I'm not able to find the right syntax to include the crl file.
I read something about hashes of the certs? But couldn't figure out how to do it.
|
The latest developments made it very clear, how easily basically all communication channels can be wiretapped. However, I think most people still ignore this fact. Especially in business most confidential information is still sent totally unencrypted (at least at my company). I wonder if people are unaware of the risks or reluctant to use encryption.
On all my emails I use a mail signature stating my GPG key ID. Probably only very few people understand why I do that. Now I was wondering if I should go further and raise awareness by adding a sentence like:
Please note that unencrypted emails can easily intercepted and read by third parties. For transmitting confidential information please use my encryption (GPG) key.
Will people care?
Should I try and enlighten people about the risks?
Do you know of a good website explaining in a simple language the risks of unencrypted (mail) communication? I would place a link to it into my mail signature. Example.
|
I read in an article that if the request is authenticated or secure (i.e., HTTPS), it won’t be cached.
But in https, burp has reported an issue stating http response is as follows:
Cache-Control: private
Content-Type: text/html; charset=utf-8
Server: Microsoft-IIS/7.5
SN: SJVPROD1
Date: Thu, 15 May 2014 20:29:30 GMT
Content-Length: 229
Is this a security breach?
|
I know the common usage of nonces in security (which is well described in this topic). However, when checking the SSL/TLS protocol, we can notice, according to the RFC, that nonces as ClientHello.random and ServerHello.random are sent in plaintext and could be easily replayed by an attacker. Why are they still used in TLS1.2 then ? Are they only there for differentiating an user for another ? They are actually no challenges performed with them.
I am here mentioning the specific case of SSL/TLS (TLS1.2), and would like to know if, in this case, the usages of their nonces have an impact on the security at any step of the protocol. If not, why has it been introduced ?
The accepted answer to this question describes why, when using the specific case of TLS/SSL, nonces aren't needed as strong authentication is used on the channel, so are they actually useless in the protocol ?
EDIT :
Nonces (date + alea) are sent in plaintext, we can therefore consider them as public data for a user, since any attacker could get them by listening the exchanges between the client and the server.
Considering 1) and the fact that the RFC specifies nowhere if we have to check the nonces at any step of the protocol, the replay attack is still possible.
Therefore, why shall we take these data as security parameters if they are "public" ? If they are not security parameters, are there usages limited to an identifier of the client/server ?
|
I am looking for a way to grant access to a secured WiFi network, based on certain external information?
For example, some server on the internet could store MAC addresses that ought to be granted access, in addition to MAC addresses stored in router itself.
Or, access to WiFi network is password protected, but it will be granted if password supplied by newly connected device matches one of the passwords contained in a dynamic list.
The idea behind this question is the following:
I have WiFi with flat rate plan. I should not resell it, but I can share it with friends and family, when they pay me a visit.
Now, I would be willing to allow access to an unknown "visitor" which happens to be within the range, provided he does the same with his WiFi. If there are enough like-minded individuals within an area, I could get access to free internet at many more spots.
However, this should work automatically, should not incur any costs on new participant, and should end its participation X days after he ceases to provide free internet to others.
Are there any security concerns? I am aware that this is still somewhat a general question, and pointing me into the right direction how this could be achieved would be great help!
Thanks!
|
Is there a way to find out in which and/or how many computers a USB flash disk entered.
And if its possible can we find out how many times a file was read/edited.
I heard that its possible , but I cant find a program to do it.
|
PCI DSS 2.0 Requirement 5.1 states:
5.1 Deploy anti-virus software on all systems commonly affected by malicious software (particularly personal computers and servers).
This requirement (although I'm not 100% positive it is the only one) caused IT security team in our company to request all the workstations able to connect somehow to the production environment (and probably all the CHD servers) to have antivirus and firewall installed.
In my opinion if the workstation's or server's only OS is GNU/Linux (Debian Wheezy in this case) this requirement is somewhat bonkers. As far as I know the main purpose of AV software running on Linux distros is to detect Windows malware, not to mention that none of those tools offers "live" protection. The best protection you can get is scheduled scan (and, since requirement 5.1.1 that is quite a problem).
Moreover Firewalls are required on all workstations too (PCI DSS 1.4). The funny part is that while virtually all Linux installations have firewalls (iptables), virtually none of them have any rules.
Can you pass PCI DSS without installing antivirus on all linux workstations and servers?
Can you pass PCI DSS without installing additional firewalls or configuring iptables on all linux workstations?
ADDED: If the AV is needed, what about requirement 5.1.1?
5.1.1 Ensure that all anti-virus programs are capable of detecting, removing, and protecting against all known types of malicious software.
I don't think there is Linux AV able to do "live protection", as in scanning everything the user runs or is about to run. At least not compatible with recent kernels.
POST-CERTIFICATION UPDATE:
Our company is now PCI DSS 3.0 certified and we did not have to install antivirus on every computer running GNU/Linux. We did not have to argue with the assessor, as they said straight away that AV is not required on Linux workstation in their opinion.
|
I'm using openssl enc -aes-256-cbc -a -salt for automated differential backups to Amazon Glacier. But I noticed that using this command increases the file size almost perfectly by 35%.
In my understanding, a block cipher shouldn't change file size this much, with my current knowledge I know it adds at most 16 bytes to the end to create the padding. But that doesn't account for 17MB+ on my backups.
What is causing this increase in size?
Log lines:
09:09:16 Created tarbal of 165 files of size 106M
09:09:50 Created /archief/2014-05-10.encrypted of size 143M
09:09:11 Created tarbal of 186 files of size 132M
09:09:52 Created /archief/2014-05-17.encrypted of size 179M
|
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