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What are the requirements for studying CEH? Is there any requirements for the programming background? And can anyone apply for it or does he has to have a recommendation for both studying and taking the test.
I am concerned about the use of bcrypt for client-side password generation. I am developing a password generation function to be used client-side, similar to PwdHash and PasswordMaker. Much has been said about the advantage of using bcrypt over faster hash functions because it slows down brute force attacks. I know bcrypt uses Blowfish internally, which is a symmetric encryption algorithm rather than a hash algorithm. So there must be a hard-coded key somewhere to use bcrypt, and since Blowfish is being used, it stands to reason that if the key is discovered, the password derivation can be reversed and the original password discovered. Since client-side code can be decompiled, the key could be easily discovered, making bcrypt unsafe to use client-side. Is my reasoning correct or have I missed something? Also, in a related question, wouldn't the same argument be valid server-side as well. A hash function cannot be reversed, but an encryption function can be if the key is known. Wouldn't it be safer to use a real hash server side, even if it is faster and therefore more susceptible to brute force attack, than to use bcrypt which is reversible? EDIT: user10008 notes below (post has been removed) that only parts of Blowfish are used in bcrypt and gave me a link. When I followed a link I found a function prototype that includes key as the last argument. So I still see the key being used to kick-start the bcrypt algorithm. If the key is required, and bcrypt uses symmetrical encryption instead of hashing, isn't the operation reversible? EDIT: Good answers from both martinstoeckli and user10008. I gave the answer to marginstoeckli because of the last sentence in the response: BCrypt can be seen as encrypting with throwing away of the key. This really cleared it up for me. Basically, we go through 2 phases P -> K ; P,K -> C and then throw away key K, leaving cyphertext C. Because we throw away the key K, we cannot decrypt back to plaintext P. Throwing away K effectively makes bcrypt a one-way function. EDIT: From user10008, the steps I gave above are more complex, however the essence is that the key K is used in the final phase and discarded. Thanks user10008.
I don't know why it seems IMPOSSIBLE to find a blog or any security expert explaining the procedure of how this 'hack' works. My wife is receiving emails from people she's emailed through Gmail telling her that she they are getting spam from her email address (3 people, one forwarded the email with single link spam). Some interesting features of these emails: the email contains her correct email (yes I know this can be spoofed) the email contains the contact's correct email So in order for this 'hack' to happen, the spammer needs access to: Her Gmail Contacts list Her sent emails directly Facebook friend emails 1-3 for one of her Contacts 1-3 for a mutual contact of both her and her contact and the spammer just tries mass guessing My questions are: What are the most likely steps for how this 'hack' occurs? What are other possible ways this 'hack' occurs? Are there ANY resources online which explain how this works: Wired articles, SE posts (I've searched, only a YAHOO CSRF), ANYTHING which gets in any more detail than future prevention? I'd love to see ANYTHING with more technical detail than 'what you do next' posts. (A Google search brings back nothing.)
Is there any way to have a flash drive encrypted and it will only open with one computer that has the key in it?
I'm using the latest version of Firefox with Ghostery and Adblock plus installed. This website somehow prevents navigation away from it. How does it do this and how can it be protected against? I can't even close the browser now. http://www.imagesnake.com/ad.html I didn't realize it at first as I was using Adblock Plus but the site causes popups containing pornography.
I want to make sure my information is safe. This website is openly china-oriented but says to secure card information with Secure Sockets Layer technology (SSL) on those pages that involve sensitive information such as credit card numbers. Is this true, and is it safe enough? Thanks!
The issue started due to setting up a proxy server on a PC connected to my network. I then realized that all of my devices that connected to the network, including PCs and phones, are all infected by an ad bot that redirects me to ads websites whenever I click on any link. I then installed Malwarebytes, Adware Cleaner and other AV softwares to clean up my PCs but not any of them have detected anything. I thought that this maybe some kind of router hacking so I made a hard reset to my router and re-configured it with my ISP, then the problem solved on all of my PCs. However, it remained on my phone. I then made a reset to factory settings, formatted everything, all apps deleted but the problem still exists and I'm being redirected to ads websites, I almost tried every AV app on the playstore but they didn't catch anything. What should I do in this situation? I don't know any other way to solve this problem. I have to mention also that this bot works only on my phone when I'm connected to my router and it doesn't work when I switch to the mobile data. On the other hand, if it is still a hacking on the router, it should also affect the other PCs. Any suggestions guys? I really appreciate any idea.
I am getting started in testing web applications, and I am having trouble verifying vulnerabilities. It seems all modern browsers have protections against things like XSS. When something like Burp finds an XSS vulnerability, I can't ever verify it when using something like TamperData. The code gets sent to the page, but it never seems to execute. Is there a browser that specifically allows things like XSS and CSRF to execute, for the purposes of testing?
I have Burp and Appscan telling me that Reflected XSS is possible due to a particular variable on a particular page. The following example is given of what Appscan injected '%252fmypage.aspx%253fHomeURL%253d%252fmyotherpage.aspx"/><script>alert(152695)</script>' and what Burp injected x.com/mypage.aspx?HomeURL=%2fmyotherpage.aspxae6fd'onmouseover%3d'alert(1)'30ec6 I have tried variations on both, with and without quotes, different encoding, and I can never get any javascript to work in any browser. Currently trying chrome with --disable-web-security, which makes no differences. I can get the code displayed in the source of the page, so I know the vuln is there, but I am having trouble actually validating it. What is in common, if anything, with what burp and appscan used to validate the vulnerability? I'd like to understand this better so I can validate easier in the future.
I'm reading about Google OAuth and implicit flow. In Google docs it says that the access token received using the implicit flow must be validated otherwise the application might be vulnerable to "confused deputy problem." (https://developers.google.com/accounts/docs/OAuth2UserAgent#validatetoken) I was wondering if someone could come up with an example which would demonstrate the vulnerability? Let's say we have Alice who is a regular user. If some adversary presents his own token (assuming that this token can only access adversary's service - i.e. Google Drive) I don't see how adversary could cause any damage. His own token will only work with his Gdrive - so Alice's files could not be affected with this. I'm sure there's a good reason for verification but can't think of one... Ideas?
Is it possible to use an open-source tool such as Cisco IPS or Cisco ASA to block incoming Teamviewer connections to specific internal IP blocks, while allowing the outgoing ones? I cannot find a specific answer on other online sources.
This article suggests that polygraphs are rather rudimentary and thus very susceptible to being 'beaten'. In pop culture we see all the time movies where polygraphs are beaten -but with great difficulty. Can this truly be done and if so, how difficult is it -does it take great skills and discipline to learn 'tricks' or is the polygraph system itself flawed?
First of all I want to excuse for the bad spelling and grammar. English is not my mother tongue. I have built a JSON communication between a front-end (website) and my Node.js web server. I want to keep in mind, that I might extend my front-end to mobile apps so I allow Access-Control-Allow-Origin: *. Now securing API to my Node.js web server is a big issue. I am new to the topic of security and want to show you a draft of how I want to build up my security before I ask my questions: General procedure: I am validating every input data on the client side - this includes not only checking if e.g. the supplied email is of a correct format, but also escapes possible XSS inputs with htmlspecialchars(). I do an HTTP POST Ajax with my validated data and access token (in HTTP header) to the back-end. In the back-end I discard requests which don't match any DB record with userid (in session object) + access token in my tokenDB. Finally. I am validating data AGAIN on the back-end as well. How I do my registration and login: Registration form with text fields which are hidden with CSS and email verification. hidden fields to prevent spambots email verification to make life harder for manual spammers Logging in: email and password is directly sent to the server and if a user record is found in the userDB the login succeeds userid + randomly generated access token + date > is entered into the tokenDB userid is saved in a session and an access token is returned in HTTP header 'accessToken' I hope this quick draft provides you with enough information for a qualified feedback. My questions: Is the validation I am doing enough? What possibilities of XSS/other threats haven't I eliminated? Is the htmlspecialchars() translation enough to prevent XSS? Did I understand the concept of the access token correctly? How do I create an access token? Is it enough to store the userid in the session? Is HTTPS necessary? -> I don't want to pay for certificates What is your overall impression of my security draft? I hope you understood my explanation of the concept of securing my API. I really hope to get some professional feedback!
We currently have what I believe to be a pretty standard scheme for dealing with password resets. Our reset links are single-use links: They expire immediately after they've been visited, even if the user doesn't actually reset their password. However, our customers are predominately (99%) businesses with aggressive spam filtering. In particular, some of our biggest customers (school districts) have a spam filters in place that perform link-scanning. They visit [up to N] links in an email as part their algorithms. When users request a password reset, the links are "expired" by the spam filter's visit before the user sees them. Are there any alternatives to the single-use link that are equally secure? Or that are secure enough to fall within the realm of acceptable practices? We also need to consider usability. Our customers are generally about as non-technical as you can get. So ideally, the password reset procedure won't become [much] more complicated for the user. Here's what we've thought of so far: Store the reset token in the session. The link would remain active while the original browser session is open and/or the password hasn't actually been reset. It may complicate the process for users who use two different devices for their email and browsing (e.g., email on phone + laptop for browsing). Expire the link after N minutes. I think I've seen this. But, I don't know what time limit is an acceptable balance between usable and secure. Expire the link only after the form is submitted. Some users may visit the link, putting it into a browser history, but never submit the form. Is that an acceptable level of risk?
I want to know whether is it possible to know the conversation/email sent via BCC can be identified by admin in some corporate companies? I have heard that email sent from BCC cannot be identified, and I want to know how this BCC feature actually works.
Yesterday, Ars Technica posted an article explaining that Android was found to be vulnerable to a UI interference attack. This claim originates from a paper published by Alfred Chen et al. of the University of Michigan a few days ago, which states that other operating systems are likely vulnerable to this same attack. In fact, this design is not specific to Android: nearly all popular OSes such as Mac OS X, iOS, and Windows also adopt this shared-memory mechanism for their window managers. Thus, we believe that our attack on Android is likely to be generalizable to other platforms. Chen et al. show that these attacks can be used to steal login information or other sensitive information from unsuspecting users with relatively high success rates. In our evaluation, we show that for 6 out of 7 popular Android apps, the UI state interference accuracies are 80-90% for the first candidate UI states, and over 93% for the top 3 candidates. This sounds like it could pose an immediate and serious risk to the privacy of smartphone and PC users. What can be done to minimize vulnerability and protect oneself against a UI state interference attack?
Suppose you have a GUI application, that potentionally may be too curious about your environment, such as the list of window titles. How do I limit application's ability to enumerate windows, capture unrelated input, access clipboard when not asked to, preserving most of normal activity? How do I give partial, not full access to X?
One of the things that has always bothered me about simple database data encryption: If the server is compromised, the database is effectively compromised. The attacker can use the same code as the app to query out the data as desired. A simple review of the app code will show where/how the key is stored and what the database connection parameters are. Of course, encrypting the data can be helpful when storing off-server backups, etc., but for this purpose the backup files could be encrypted entirely, instead of fields, saving some headaches with queries, etc. Generally, making sure the server is secure is the best practice. But, what if the data must be protected from everyone, sys-admins included (much like the way we treat user passwords, through hashing)? Ultimately, I'm wondering, how can an encryption key be protected, so that it is not accessible by anyone without the secret, even the application code. The only approach I can think of is the key must be provided by the user at run-time (it isn't persisted on the host machine, period). I imagine the first issue is that if a user has access to the server, there is probably a way that the secret could be sniffed at the point of entry, or if the key is stored in memory by the app (e.g. in a session variable) this could probably be exploited as well. What are the other (likely glaring) problems with this approach? Is this just reinventing the wheel? If so, what is the best practice when data security is critical, even from super-user roles? This question may be somewhat similar to: How to login and encrypt data with the same password/key, except that I'm asking if the concept is even a good one, not how to implement.
Looking at the Google geolocation API it claims: Geolocation API returns a location and accuracy radius based on information about cell towers and WiFi nodes that the mobile client can detect. Assuming a phone is in airplane mode or has no sim card and thus cannot connect to cell towers, and assuming that GPS is also disabled, how can a phone determine its location based off of only the wifi networks in range? Is Google using the collected data from street view wifi MAC addresses, and combining it with the GPS from the street view van? would this correlation data be stored on the phone, or downloaded as-needed via a data connection? or does this only work with known wifi networks? is it based off of the MAC address or the wifi network name? Is this Google-specific or are there other API's/companies that can do this (and not rely on Google as their back-end?)
I recently recovered a zip archive with some files I need access to, but I can't remember the password. All I can remember is that the password was short (around 3-4 characters), and contained only lowercase characters and possibly numbers). However there is no Incremental mode for this particular situation in John the Ripper. The closest there is is lanman, which also increases the set of possible passwords dramatically by including uppercase chars, which I'm positive the password includes none of. Although I can edit the john.conf file so that a specific mode goes only to 4 characters, for instance, I don't know how to customize the set of characters to try. How could I do this?
Few different scenarios: 1a) On public McDonalds wifi, logging in gmail account (or any account such as skype). Can a random user who is using the same wifi somewhat intercept the signal and figure out the password? 1b) Same situation as above, except that gmail is already logged in and accessing gmail. 2a) On random public wiki, logging in gmail account. Can the owner of the wifi figure the password out? 2b) Same as above, except already logged in. I assuming that in the 2a case, they can, but I am not sure about 2b
A security conscious friend of mine was attempting to generate entropy using random dice rolls to generate a random password, and I became curious about the security of random number generators and whether or not she could do the same by simply thinking of random dice rolls. Would it compromise the security of password/key generation to use human-generated random numbers instead of random numbers from a dice or a secure random number generator? I can see how the standard random number generators included in many programming languages might not be cryptographically secure in known and exploitable ways, but how about the random numbers generated by the brain? When I asked her, she stated that humans were terrible at generating entropy, but I'm not sure that this is the case. How do humans rank in the generation of key entropy and would it be possible for a human mind to take the place of random number generator for key/password generation without being exploitable?
I suppose this is related to What is an intermediate certificate authority? but I think my question is a bit different so I'll ask it anyway. Why do most modern certificate authorities (e.g. VeriSign) require two intermediates? And if more than one is necessary for security purposes, why "just" two? Why not three? Or four?
We have a number of internal development environments that use weak passwords in the Auth and SQL components; particularly using passwords such as "password" or "Password1". These are obviously changed for UAT and Production environments but how guilty should we feel about relaxing our habits for the sake of ease while developing solutions?
I started looking at OAuth - Google's and Facebook's implementation. Both of the implementations, in the authorisation flow, seem to send the "Authorization code" back to the web browser. I was wondering what is the benefit of sending the code to the browser vs just hitting the redirect_uri from the authorisation server? If we send code to the browser we risk that someone somehow gets hold of it while the risk does not exist if the code is sent straight to the server (redirect uri target).
I try docker with a simple webapp : docker run -d -v $(pwd):/app -p 8080:80 image_name I have docker listen on 8080: tcp6 0 0 :::8080 :::* LISTEN 13304/docker So I can test my web app through localhost:8080 I use iptables with UFW and I deny incoming except: 80, 443 and 22 But surprisingly, if I do a netcat from the Internet to my machine on port 8080 I can have access to my web app !! Docker must do something special because if I start socat like this : socat TCP6-LISTEN:8080 TCP4:www.google.fr:80 I see : tcp6 0 0 :::8080 :::* LISTEN 11577/socat But this time I can't connect from the outside ... UFW do the his job ...
Is it possible for the developer of an open-source software to hide a backdoor without getting caught? Obviously open-source is superior to close-source when it comes to transparency, also I am aware of the fact that open-source does not necessarily means 0-day-free (if there is such software) but has it ever happened to discover a backdoor in an open-source software?
I have a scenario where I evaluate two different types of attacks on a distributed network of nodes (you may also call it a multi agent system). On the one hand the attacker is able to read incoming and outgoing messages of nodes. That is called a sniffing attack. On the other hand he may pose as is a valid node (going through registration, etc.) and has access to internal control data that is sent through the distributed network. This can be described as an inside or intruder attack. But is there a more specific name in the literature for this kind of attack? Thanks in advance
I dialled a cell phone number and it rang but with no reply. I asked the person later why they did not answer and they said the Sim card was not in the phone. In fact, it was in a purse.... Is this possible? Can a Sim card that is not in a mobile ring?
I traced a header on an email I received, the person claims to have sent it from Maryland, but I traced the IP and it shows shows San Jose, CA and also contains loop backs, ??? Is this possible?
Per current security recommendations & browser support, is it okay to have an https iframe in an otherwise http-only set of pages? Is this not a dupe? It is, but I want current trends because when I tested a few months back browsers warned me about mixed content, but now when I do an iframe of a secure login page overlay from my own domain I don't get any warning. (URL is a.com but it points to my own local host, main url us http://a.com/, which has an iframe that comes from https://a.com/login) I presume it's because https is not at fault and it was JavaScript that led to the vulnerabilities and now that is fixed? Tested in FF 31, Chrome 36, IE 9 I did see: Specific risks of embedding an HTTPS iframe in an HTTP page ; Specific risks of embedding an HTTPS iframe in an HTTP page ; Is posting from HTTP to HTTPS a bad practice? ; https://www.owasp.org/index.php/SSL_Best_Practices I understood that the risk is that the user could have an addon/malicious program that changes the iframe's source. If the user's computer is so badly compromised aren't all bets off anyway? Should we tell our client, even in 2014, no https login iframe? If the user wants to login, refresh page to the https version or redirect the user to other login page and post login can come back to http in safe areas (non checkout and account related). I know it's not much of a computational thing but for some reason the client is fixed on the idea that some pages are better http or https (default http though user can change to ssl manually)
At work we use a central portal that provides basic SSO functionality to other applications. In addition to verifying the SSO data sent, all of our existing in-house applications (used by the public) also check the referrer header to make sure that the user is actually coming from our central portal. However, we just experienced an issue where a JavaScript code change in the central portal caused Internet Explorer to stop forwarding the referrer header, which brought down all the apps that check that header. My question is whether checking the referrer header provides any real world security improvement over just checking the basic SSO information (encrypted user ID contained in a cookie)? If it doesn't, is there any documentation/research/etc. that I could use to prove this to management? I should also mention that unfortunately the central portal is a third party app which we don't have much control over ... so basic SSO information in the form of an encrypted cookie and referrer header information is all we have to help secure things.
I am thinking about a creating short security demo to get people interested in the security topic. I've had a couple of ideas just want to see if anyone has anything else interesting. Edit: I was brought to my attention that this question is too broad and I will have to agree with this. In order to narrow it down I will ask this instead: Can someone think of a simple "magic trick" or game that can be used to gather data for a very simple social engineering hack? If people feel that this question is still to broad I will remove it. Thank you.
I work at a large university and have a computer supplied by my employer. I would like to find out whether my employer is snooping or can snoop on my files or activity on my computer. Can I find that out? How would I go about? There is apparently some sort of remote management that the help desk can use if I call them and accept their request to log onto my computer. Program updates are also pushed out automatically. The machine runs Mac OS X, I have admin privileges and can install any software I want. (Note that this is a technical question, not a policy one. Also note that I understand any computer can be hacked. This question is more pointed towards assessing typical threats from my friendly sysadmins and their equally benevolent bosses.)
I just realize that this website knows the real ip address even if you use proxy ,i found this question, so start to test every possible way,first, this website don't have a X-Forwarded-For or X-Client-IP in its source code,second, this site don't just tell you are using proxy,it show your real ip address which it is not something that HTTP-header can tell.so how this website actually knows our ip address? is it some kind of trace back even if i disabled track data on Firefox even if we disable javascript! it shows real ip address!!
If a WorPress application that uses the Akismet wordpress plugin has certain directory listing exposed publicly, like, akismet-en_AU.po and the other .po files, and directories like plugins, themes, uploads (primarily containing just image files) etc.only accessible, should this be considered a security flaw ?
I'd like to use a key-value store (cassandra, redis, ...), but I don't trust the server. The clients have a shared secret, and I'm using that to encrypt the stored values. But what is the proper way of encrypting the keys (not the crypto-keys, the key-value store keys)? The store compares keys in queries, so each plaintext-key must have only one corresponding encrypted-key. Obviously, if an attacker gets hold of the encrypted-key, it must be as good as impossible to find out the plaintext-key. Less obviously, if an attacker can guess the plaintext-key, it must be impossible to get the encrypted-key without the secret. I don't want an attacker to be able to confirm if a certain key is present in the key-value store. Collisions (different plaintext-keys with equal encrypted-key) should be so rare that they cannot be created on purpose by an attacker. Symmetric encryption with Random initialization vectors or hashing with salts is prohibited by (1). A hash of the plaintext-key without salt does not meet (3). I see two options: encrypt with a static IV. hash(secret \|\| plaintext-key) The first feels very much like improvising a hash function with a cipher. It would also allow decryption, which I don't need. Edit: Since the IV isn't random, plaintext keys with equal prefix will still have the same prefix in ciphertext, with may allow reasoning about the plaintext. The later one is storing the hashed secret, but without the usual precautions, such as salting and key stretching. Edit: it is also vulnerable to Length_extension_attacks.
Does anyone have any examples of real-life applications that doesn't require "strong authentication". I am looking specifically for blog posts or even scientific papers that argue that "strong authentication" is not required for all applications ... sometimes you need to authenticate users using IP addresses only, for example, but anything more than that would be unnecessary ... EDIT: Ok, I think I need to explain myself a bit further. I am looking for an argument from a developer or a business owner or a scientist (an official statement, e.g. scientific paper, or semi-official, e.g. blog post) that argues for a "non-strong" authentication. The business owner's insight is the most important thing (that I'm looking for). For instance, @Florin Coada's example is great, but it would be better to see Apple's insight on the matter. I tried googling for days, but keywords I'm using are bringing completely irrelevant results. EDIT 2: The answers are awesome, and maybe I should extend the question a little bit (for the last time). Would there be any kind of application, where the risk of "security breach" is high, like privacy breach of users of your service (by "power users" like skilled programmers), yet you choose to do a "weak authentication"?
The famous Mat Honan hack got me thinking about e-mail password recovery, and how any link in the chain can break all the links preceding it. In Mat's example, that link happened to be the last link, and the entire chain broke down. Specifically, Mat used his GMail address as the recovery email for all his services, and used his Apple e-mail as the recovery address for GMail. Therefore, once his Apple e-mail account was compromised, GMail was compromised, and all of his services soon followed. I understand the need for email recovery for web services in general. However, using an e-mail recovery address for an e-mail service sounds like adding a redundant link to the chain, doubling your points of vulnerability (now your attacker can hack into either your primary or your recovery email account). Also, what is the recovery email you use for your recovery email? Having a recovery recovery e-mail adds yet another point of failure, and when you finally stop the chain and don't use one, you could find out you're locked out of it just when you need it the most! True, the attacker may not know the address of the recovery mail, but as Mat's case demonstrated, he can deduce it (in his case figuring out Google's obfuscated pattern, where they hide some of the characters). And if you make it hard for them to deduce, you're making it hard for YOU to deduce - most of us use a single E-mail address, and if you set up a special address only for verification purposes you are likely to forget it a few years after. I had a couple of ideas: Don't use a recovery e-mail for your primary e-mail at all. Simply activate 2-factor authentication and make it your strongest link (which you should do with all your important services anyway). Use a friend's e-mail address. If you have a friend/family member that you know cares about security as much as you do (and thus has 2-fact auth set up as well), you could use his address. Now an attacker has to hack two people, and it's highly unlikely he'd even guess which mail he needs to hack - you however will probably recognize it immediately (I suppose you could fall out of touch with that friend after many years, so perhaps a family member is preferable here). You could even set each other up as mutual recovery enablers. I'd love to hear your thoughts on my analysis.
What options are available for transferring data between unix machines separated by an air gap? USB flash drives Optical media eg CDs and DVDs Printed paper and Scanning+OCR QR Code software, displays or printers, and cameras Pen, paper and typing! Smartcards / ISO 7816 Contactless / NFC / ISO 14443 Each of these have pros and cons, and I'm having a hard time identifying the smartest way to move things like certificates, private and public keys and other relatively short data, to and from an offline machine.
I am not sure how hashing works exactly, all I know it is impossible to reverse it. All hash types have X amount of characters in them while the phrases and made up words can have an infinite quantity hence infinitely more times than the character counts in a hash. So do hashes repeat themselves?
I'm making a website that has an extended forum feature, where users can login, post comments, etc. I'm making the feature where the website stores cookies in your computer so the next time you visit the website, it logs you in automatically. I've heard not to store explicit username and password in a cookie. So I decided to store the user id in my database as a cookie value. Essentially, all information when you use the site can be obtained by querying the database again by this user ID. Then I just realized that if you manually edit your cookie and place a random user ID, anyone would be able to access any account! All the functions in the website such as new comment, new topic etc. are can be accessed just by supplying your user ID. What is the correct way to have users log in automatically on my site without exposing it so anyone can log in?
It seems many sites use 3rd party flash ads, those ads could be design to attack user. Do those site know which ads are safe or not? Or they just transfer any ads to user browser? In general, how to know 3rd party ads are safe or not?
I would like to encrypt some authentication tokens using AES 256 (not tied to this algorithm but it seems to be a reasonable choice). These messages are usually very short at 128-256 bits. I'm concerned foremost about the security, not very concerned about ciphertext length or performance in either encryption or decryption. These are shared secrets so I have to be able to obtain the plaintext. I am curious if any additional padding beyond what is required for the message to match the blocksize is beneficial. To clarify this is not a question about padding the message so that it can be run through the encryption algorithm, but rather would I gain anything by padding to the message to say 1024 bits vs. 256 when the message is very short. I am already using an IV as I am reusing a key. If I do pad to an additional length should I just use a single character, or should I put in a random stream of data? My concern is that by only padding to 256 bits I may potentially betray the size of the secret (although most of them are shorter then the blocksize).
A very simple example... <div id="cat"></div> <script> document.getElementById("cat").innerHTML = document.referrer; </script> or <script src="' + document.referrer + '"></script> I've tried simply sending the request and adding a referrer header, but that doesn't seem to echo onto the page.
When you encrypt your home folder in Ubuntu and Debian, it protects not only the file contents but also the file and folder names. Yet I see that updatedb and locate works in Debian. When I run locate, it finds files that are in my encrypted home folder. Does updatedb store the unencrypted file and folder names of your home folder somewhere?
What I understand about reflected XSS is ... When a web application is vulnerable to this type of attack, it will pass unvalidated input sent through requests back to the client... [1] Assuming that my webapp has a CSRF validation on server that checks for a valid CSRF token for all requests. It will give proper error if it receives any request not containing CSRF token (this error is a simple string, it has no attack vectors). For the sake of completeness, let's also say that I have proper security measures for preventing CSRF token from being stolen or guessed. So is it safe to assume that CSRF tokens also prevent reflected XSS attack because both of these are true: The server doesn't reflect anything if CSRF token is not present. The attacker cannot have or guess CSRF token.
Suppose as an attacker i want to carry out a Ping or SYN Flood attack.. I can change the source IP of the packets generated at my machine to a false/spoofed public IP address so that replies go to that spoofed IP to avoid detection. A WiFi router or any device for that matter .. would it drop the packet if source IP was a spoofed public IP or does it forward the packet to the destination or does NATing take place and the reply comes back to the router public IP address? How would IP Spoofing work in this case? ..what is the general behavior of networking devices here Edit: If there are so many variations in behavior of networking devices .. then how do Botnet operators manage to carry out DDoS from their slaves .. since majorly bots are in NATed home/business environment?
What is a good method to receive security alerts? Email is the first thing that springs to mind, although it is susceptible to MITM attacks (e.g. an attacker preventing the email from being delivered). Although this is not really a practical attack as the MITM will not usually be suitably placed for this to work (often email retrieval is done over SSL, and it is hard for attackers to intercept the actual delivery). There could be other attacks though such as the attacker DDoSing the mail server to prevent alerts from being received. Text message sounds a good way, however the number of alerts triggered could be high and unsuitable for this format. Another way may be a mobile app so that alerts can be received at anytime or anywhere. However, if the app is not currently installed alerts will not be received (e.g. users changing phones, etc, whereas formats such as email and text message are universal). We are looking to monitor an inhouse, internet facing application deployed to the cloud from a security perspective and would like alerts such as the following to be logged and possibly alerted upon: Incorrect password attempts. Forms submitted with incorrect CSRF tokens. Attempted access to URLs that the user should not be able to access (e.g. if the user tries to go to /Admin or if there is any parameter tampering - /Project/1234 is changed to /Project/4567 by the user). In a nutshell, any security threats that can be handled internally by the application that we would like to know that has been attempted. We are not interested in trying to detect attempts at XSS or anything "extra" outside our application functionality, simply we would like to know when one of the existing security rules are triggered so we can monitor it and possibly act upon it. By security rules I mean the business logic within the application in order to secure it so this system would be actually implemented at code level to decide on what we should be alerting on. Security events are already logged, however checking these logs is a manual process. We could introduce the concept of thresholds to reduce false positives. i.e. one incorrect password attempt is only logged, however 5 incorrect attempts in a row against an account of from a particular IP triggers an alert. So to summarize I am looking for a secure and reliable way to be alerted when a security event is triggered. Either through custom code or some other method as I have a feeling that this is an already solved problem. This will be combined with IDS in future, so this is purely from the internal perspective of the application. I am currently thinking that text and email solution might be suitable, however the text and email trigger only once and only display a link to log into the monitoring application to view activity.
I recently nuked my HDD(s) via a Windows program (Disk Wipe to be precise: http://www.diskwipe.org/), now everything is fine when I try to retrieve the information on that disk by any program I can find except for a couple of programs which have noted that the $RmMetadata folder still exists with files such as $TxfLog.blf within them. An example image is shown below: I have done a litle bit of searching to try and understand exactly what these files are but no one seems completely sure. Could this data still existing pose information leakage problems for a nuked disk if I were to, say, sell it on?
How can I prevent the installation of Chrome extensions on desktop?
Is there a way to disable the use of anonymous navigation window (an Incognito window) in Google Chrome for a computer?
Because Mylar does the decryption in the browser, the key is never stored on the server. Nice. This moves the threat to the browser, where, if the attacker is able to get a malicious script to be served to the browser along with the Mylar related app/data, then the script could just harvest the decrypted data. So, how does Mylar ensure the app code that is served to the browser isn't malicious? I see in this document: http://www.mit.edu/~ralucap/mylar.pdf Verifying application code. With Mylar, code running in a web browser has access to the user’s decrypted data and keys, but the code itself comes from the untrusted server. To ensure that this code has not been tampered with, Mylar checks that the code is properly signed by the web site owner. This checking is possible because application code and data are separate in Mylar, so the code is static. Mylar uses two origins to simplify code verification for a web application. The primary origin hosts only the top-level HTML page of the application, whose signature is verified using a public key found in the server’s X.509 certificate. All other files come from a secondary origin, so that if they are loaded as a top-level page, they do not have access to the primary origin. Mylar verifies the hash of these files against an expected hash contained in the top-level page. So an app code hash/signature is checked. Nice, assuming this hash/signature hasn't been compromised we can know the codebase is valid against a specific release. I also see that Mylar uses two origins. What if both origins are compromised? Also, could one of the origins be a specific git repo commit hash? What are the possible issues with somehow interfering with this verification step? I'd love to understand more about how this specific security feature works and how it is secure.
Hello my team is tasked to perform security focused training for developers (.NET and JAVA). I have used WebGoat to demonstrate OWASP Top 10 type security vulnerabilities and am looking for a similar tools / software to for demo and labs to cover security focused topics in .NET and Java. The goal is to show insecure code and then how to write secure code Any help is appreciated
My gut feeling is that the following should be attackable: $("<td><a href=somefile.php?url="+encodeURIComponent(somevar)+">Download Here</a></td>"); In contrast to $("<td><a href=\"somefile.php?url="+encodeURIComponent(somevar)+"\">Download Here</a></td>"); For a cross site scripting attack if the user has control over somevar, yet I can't seem to find the specific attack. Am I mistaken?
I am a bit confused about securing the secret encyption key. Here is the scenario: I need to encrypt some data (file) This data will be read by a program (say written in C/C++). Both the program binary and encrypted data will be accesible to some arbitrary user. However, in order to read the data the program needs to have the secret key that was used to encrypt the data. One possibility would be to hard code the secret key into the source code of the program itself. However, the key can be found out even from the compiled binary! I also do not have any possibility of taking input from the user for password/secret key etc. I also don't have any network access to request a server to send the key. Please, assume the OS to be linux/linux like. So, the question is, how can I secure this key?
Does multi-factor authentication provide any additional security benefits on top of doing a better job at correctly identifying and authenticating users compared to single factor authentication? In other words, if a system could perfectly identify users based on say biometric cues, is there still a need for additional factors to authenticate a user? As a real world analogue, if I want to limit use of my car to only say my spouse and I'm confident I can recognize them with 100% accuracy, would there be any additional security benefits to having a password or a token type of device between us?
As in md5(md5(md5(x)))... I can remember coming across that in some piece of code. If the attacker can somehow reverse md5(md5(md5(x))) into md5(md5(x)) then he certainly can reverse md5(md5(x)) into md5(x) and the x. However if it takes some good amount of time to reverse the first hash then hashing the hash can slow him down. I cant make up my mind on this issue hence the question
I've noticed a brute force attempt on several different WordPress installs that know the right admin user name for those respective sites... It seems very strange that the hacker would be able to find the username but not the password... Furthermore, I've checked these WordPress builds, and I do not see where they are leaking that information anywhere - albeit that is likely the answer... While I am not worried about the attacker getting through thanks to a whitelist I've already implemented - I am concerned that whatever vector this hacker is using could be used to obtain more sensitive information.
I'm working on a web app at the moment where we’re trying to remove any user friction and excess steps from our user creation page. To avoid computer bots completely spamming our app we need to have a some sort of CAPTCHA but this would take away from the main idea behind the app which is simplicity. When looking through the suggestions of alternatives here on Stack Exchange they all seem to still take away from the UX and leave room for bots to work around. Suggestions here: Anyone using Asirra in production? Are there similar alternatives? Is there a true alternative to using CAPTCHA images? https://ux.stackexchange.com/questions/50051/is-there-an-easier-and-more-user-friendly-alternative-to-captcha https://ux.stackexchange.com/questions/51864/captcha-on-mobile-what-are-the-alternatives This got me thinking, why can't we detect whether a user is real or a bot using a series of anti-bot methods behind the scenes such as honeypots, time-stamps, rogue POST and GET requests, whether JavaScript is enabled, checking HTTP header and others. Is there a technical reason why this hasn't been done? Thinking about writing up a library myself otherwise :).
My apologies if this is too subjective, but I am looking for advice on best practices. We maintain a small program written in Python that runs on our customers' servers and communicates back with our servers. We are using Python's ssl module which relies on openssl to protect this communication back to our servers. This program is run on older Linux systems (think RHEL5) as well as Windows variants. (Yes, the ssl module doesn't come by default with Python 2.4, but please ignore that issue for the sake of this question.) Our plan is to include a file with the program containing the certificate authority that issued our current SSL certificate, as well as some other authorities that we may use in the future. That way, we know that no matter what is on the customer's servers, our certificate authority will be trusted. Is this reasonable, or does openssl provide a good enough list of certificate authorities even for old openssl versions that we should not need to worry about this ourselves? Are there any issues we should also consider with regards to providing our own certificate authority list, beyond just locking us into that list for future SSL certs?
What is the vulnerability level if the anti-csrf token is not sent with every post request? (If the vulnerability levels were high, medium and low). I understand for critical functions like login etc you would need to include csrf token. What factors should I consider when deciding whether or not to implement CSRF for each set of permitted requests in a web app? Update: I found this article here that explains need for csrf token for each request It is interesting that more and more web apps are considering it for each request.
I use my MasterCard credit card for online transactions which uses SecureCode for preventing online frauds even though hackers knows our credit card details. I have come across many sites which is asking me to enter SecureCode. But recently i made one transaction in one online website, which is just taken my card details. I was waiting for SecureCode to be entered, but it shows transaction success and I got message money deducted as well. Why some sites allowed by MasterCard to not required SecureCode ? what does it mean ? It's more prone to online fraud.. isn't it ? Using Smart card readers,security tokens we don't need to enter SecureCode i read from wiki, but that article needs citation. so anyone can clarity me on this. What's happening in transaction ?
I observed that sometimes my facebook https connection changes to http after using the site for a while. Is it possible for ISP or somebody in between to do such a thing by throttling the net speed ? Or, how such a thing is possible ? I thought facebook, like google, is always https. Also, this happened when I have installed https everywhere plugin for mozilla.
VPNs are accessed by the user with credentials so that the information is encrypted. There are credentials that you download to allow this. Since you don't physically, in person get the credentials from the VPN provider they have to be downloaded which means using the internet. Now I know HTTPS is used but HTTPS is weak at best. Government organizations can look at HTTPS data and they don't have to immediately either. Your ISP is logging your web traffic anyway even if it's encrypted, they might break it in the future. How can you secure the actual security key/certificate which you are receiving from your VPN.... I realize this might not be possible without an in person physical exchange but isn't this a security killer for VPNs? This will protect you from rogue unsecured public WiFis and such but your ISP and government agencies will be able to get the VPN credentials which you downloaded through HTTPS. Is there a way around this? Are there other techniques that combat this?
I am running a scan against one of our servers from the Qualys SSL tester site and it says that my server "does not support forward secrecy with the referenced browsers". What exactly does that mean? My server is setup to use ECDHE_RSA_* ciphers which I know do support forward secrecy if negotiated and is recognized on the Qualys scan. Is this a browser issue since it says "referenced browsers".
What's the difference between MITM attack and sniffing? Also could anyone name a few other attacks similar to those?
During manual SQL injection testing I came upon this. Is there any way to bypass these filters that supposedly prevent a UNION based attack? <?php error_reporting(0); include('db.inc.php'); $id=strtolower($_GET['id']); $counter = 0; if(strpos($id,"union")!=false){ $counter++; } if(strpos($id,"select")!=false){ $counter++; } if($counter==2) { echo "Go Away Get a Life"; }else{ echo "<font color=green size=4>Query Coming is : ".$id."<br/></font>"; $query = "SELECT username,password FROM admin WHERE username='".$id."' ORDER BY 1"; $result = mysql_query($query) or die(mysql_error()); while($row = mysql_fetch_array($result)){ echo "Username : ".$row['username']."<br/>"; echo "Password : ".$row['password']."<br/>"; } } ?> Also, what is the best way to prevent a UNION based SQLi attack?
I'm actually interested about zero-knowledge storage system. Those system where the storage provider claims he can't have any access to the data stored. As far I know, the data are encrypted using a symmetric encryption system, such as AES or another, But those systems need a key to function. So what happens to the key? Is it stored? Where? If a user connects from another location, and wants to retrieve one of his files, he must retrieve the key first. So if the storage provider stores the key too, he could have access to the encrypted data. It's like having a chest locked and the code on a paper next to the chest, and then claiming that you couldn't open the chest. So is there a flaw in that? I'm I mistaking completely about those zero-knowledge system? If they can finally open the file, how some of them could escape justice by saying "We can not know that we are hosting illegal files?"
I work for a firm that has a marketplace on the web. We want to make a link with a token that stops an ad on the marketplace without the user being logged in. Someone suggested that we make a token from this: base64urlencode(md5("salt-adid")) adid is information known by the user. salt is just a secret word. Given this is this solution secure? The user can know the adid. Will it be possible for a malicious user to calculate the url for stopping an ad? How can this be change to be more secure? EDIT: Xander pointed out that something was unclear and I will try and elaborate. "It's not clear to me why you need a token at all. Is this just for some logged out users rather than all logged out users?" It should not be possible for any user to stop the ad just to owner. We will be sending the url to the owner so he/she can use it if they want to stop the ad. So it is just for some logged out users.
Kind of a silly question, but I'm genuinely curious: (in part because I recently saw several questions that refer to "nuking" a hard drive...) what would a microwave DO to an HDD? Would it erase data on there, or at least corrupt it enough that it's difficult to recover?
I just read the question: Does microwaving a hard drive erase it? and now I am curious too... does microwaving a CD (or for that matter, DVD, or blu-ray) erase it? My initial thought is that some data would remain, but that it would largely corrupt the data. Would microwaving the CD completely clear off any data though, including small pieces of data, such as passwords? This is not a dupe because a CD does not have a protective case around it like a hard drive does, so the result will likely be different in the case of a CD.
I have 2 or more web applications that need to be able to communicate together using a web service interface. Information All applications are using TLS/SSL (https) All applications have access to the same database and that database can only be access by these applications My problem is that I don't want anyone else to be able to use the web service. Meaning that only the applications should be able to call the web service to get information or execute an action on another application. Is there any "simple" way to do that? I figured that since only the applications have access to the database, I could probably use it as a trusted third party to validate the identity of the one calling the web service. EDIT There was some confusion with the current setup so here are some additional information The applications and the web service are the same thing. Each application define a web service interface to enable the other applications to communicate with it The applications and the database are all hosted on the same server and it's a dedicated server that only host those applications and that database and it is run by "myself" All the applications are secure and require authentication to be used I need to use a web service instead of using the database to communicate between the applications because each applications is using a different language and the business logic is all in the applications code. This business logic code need to be called when the applications communicate together.
If ISP blocks TLS channel while a user is using Tor, can he read the Tor traffic, since Tor uses TLS encryption ?
Can ISP block HTTPS selectively i.e. certain websites cannot be accessed using HTTPS while others can be ?
I want to run a TOR node using a small ARM device mini server. I already have a good firewall set but feel a bit uncomfortable when giving away my IP address to the open web by opening a port. If I use a VPN service would it help obfuscate my personal IP address? What are the implications if it does not?
I was reading hashcat's About page, and the stats are listed in terms of c/s....is that "Cracks per seconds"....the 'c' part seems wrong, I'm just guessing. What is 'c'?
I am in the current process of renewing my SSL cert for my website. I also have a mobile app for my site. I want to use the same cert from my website in my mobile app. How can I do this? Thanks - I appreciate all feedback
I have a service with "try it now" experience that currently offers a "one click" effort. This service has a pool of N resources (lets say 50). Each new resource takes about 1 hour to generate. How can this service be protected from a malicious user to empty my pool of resources? We have circled around some suggestions but so far nothing seems to resolve the issue: Using email validation (emails can be easily faked today - for example with yopmail) Using some external Login (Google , Facebook etc.. ) - again, users can open as many accounts as they want. IP request throttling - IPs can be changed easily. Services like Incapsula or Cloudflare can't really help in this scenario. Captcha will have no effect Serious candidates have serious user-experience implications and do not seem to be sustainable - such as call each user that wants to run the demo and talk to them, and then manually pass them some link. perhaps using email validation with some sort of email blacklisting by regex (e.g.: .@yopmail.) can do the job. What is the right way to tackle this scenario?
I know it's possible for a computer to be infected just by visiting a website. I also know that HTTPS websites are secure. To my understanding, "secure" here refers to "immune to MITM attacks", but since such websites have certificates and such, is it right to assume they are "clean" and non-malicious?
I've been checking out various TLS certificates lately and noticed that most of the banks seem to have the following two issues: 1) They do not offer perfect forward secrecy 2) They are still using RC4 So far, all the ones I've checked (TD, JPMorgan, CIBC, Wells Fargo, Bank of America, ING/Tangerine, RBC) use TLS_RSA_WITH_RC4_128_SHA Though actually CitiGroup and Goldman Sachs are using AES in CBC mode with 256 bit keys, instead of RC4, but still, no forward secrecy, and I would think GCM+SHA256 is better than CBC+SHA, even with 128 bit keys vs 256. On the other hand, google, facebook, linkedin, and bitcoin exchanges/sites do offer perfect forward secrecy (typically with ECDHE), and unanimously use AES in GCM mode with SHA256 and 128 bit keys. So my question: why have our banks not upgraded their security, especially given recent attacks on RC4 (though they are mostly theoretical, they do point to possible issues, and RC4 is generally considered less secure than AES)? Also, why would they not offer perfect forward secrecy? Is that an oversight on their part, or possibly for regulatory reasons? I nearly emailed my bank about this today, but figured I'd throw the question up here first. Of course, cyber attacks on banks are all the rage these days - they ought to use the best encryption they can.
For the early ChangeCipherSpec attack, the attack would affect client with all version of OpenSSL and server with OpenSSL version 1.0.1 and above. My question: If two mail servers are communicating with each other, would they be susceptible to such attack (assuming they are using OpenSSL version 1.0.1 and above) Thanks in advance!
I've looked around on Security.SE, but couldn't find much related to the following problem: I recently signed up for Chase Quick Pay as my method of being paid by a part-time job. I've heard of stupid password requirements, but never stupid username requirements. When I enrolled, I didn't really take into account how weird it was (I really should have, because I have forgotten my username twice in the past 3 months due to the policy): Now, the Stack Exchange engine has so graciously pointed me in the direction of a question with a good answer by @Polynomial that says it all in the first sentence: The authentication strength should come from the password, not the username. So, quite simply put: what is the point of having requirements like this on a username? Edit: For clarification - are there any real security benefits to having these kinds of username requirements? Bonus: I just looked at my own bank's username/password security policies, and found the following (not that abnormal): Note: I don't really understand the point of disallowing 'X' as the first letter... anyone who can answer that gets a +10!
Does such attack exist? Forgive my wild imagination but is it possible for a hacker to pretend/try to communicate with a service on the server and when the firewall examines the traffic it get's poisoned or taken control of? If such scenario exists what is the name of such attack? To my understanding firewalls are unlike proxies, they don't receive the traffic and regenerate it but they only examine it which makes things more difficult
It's clear that someone listening on a network could still find out what website I visit over HTTPS (as discussed here) but what about when surfing in a VPN? What exactly can the underlying network (not the VPN host) see? Can it see what IP addresses (websites) I connect to whilst using a VPN?
I would like to make this story as short as possible since my question is not that long, I have worked with journalists previously in war zone where we investigated the involvement of EU IT companies in selling monitoring software to Dictator regimes owned ISP companies, One was a french company that I can't mention their name nor their software but the software was capable of simply monitoring anything from clients PCs even if it was encrypted.. it would be decrypted. So my question is in case of being connected to VPN with SSL support and Certificate server/client verification plus user authentication. how secure can user's browsing be? Is it possible for the ISP company that user is connected to, to know what anyone is browsing regardless if he/she is connected to a secured VPN connection?
My question is about the difference between signing and encrypting. Why would you still sign something if you are already going to PKI encrypt it? Doesn't the PKI encryption inherently provide authentication, integrity and non-repudiation? ==added later=== What if I use my private key to encrypt my message. Then anyone can decrypt this message with my public key so it is not private, but all who do, know it is from me because it was decrypted by my public key. Also all know it wasn't tampered with precisely because they could decrypt it
Does Shared key and Pre-shared key mean different thing ? Currently reading Text , Security+ Guide to Network Security Fundamentals.
We have received the below finding from an IT audit. Missing Secure Attribute in Encrypted Session(SSL) Cookie: It is best business practice that any cookies that sent over (Set-cookie) an SSL connection to explicitly state secure on them Can someone can explain what they are and how to secure them?
I'm trying to understand how null byte injection attacks in PHP code used to work before it was patched in PHP 5.3.4. I have this sample HTML page that is a somewhat modified version of what's shown here: <?php var_dump($_GET); echo '<br>'; $file = $_GET['file']; $path = '/var/www/' . $file . '.php'; echo $path; if (file_exists($path)) { echo "file exists!"; include $path; } ?> This code is running on an Ubuntu 12.04 system running PHP 5.2.17. I would expect a URL like http://localhost/?file=../../../etc/passwd%00 to work, but instead I see \0 printed literally in the string: array(1) { ["file"]=> string(21) "../../../etc/passwd\0" } /var/www/../../../etc/passwd\0.php What am I doing wrong? How can I get null byte injection attacks working on my local machine?
Let's say I have a system which use something you know, like a password, and something you have, like a code sent to a cell phone, to authenticate. Is there a preferred order to ask for the password and the code? Should it be the password first then the code sent to the phone or the opposite? Edit The answer should be : Password first but validate both at same time. Explanation here
At home, I have a simple ISP supplied router where I have set up a WPA2-PSK wireless network for our laptops and other devices. While I played around with Wireshark, I noticed that I could use my laptop to see what my tablet is doing in the internet, without the tablet noticing anything. I think this works because all devices have the same wireless key and there is no way to send packages to one recipient. The recipients are usually kind enough to ignore all the packages that are not addressed to them. When people visit, I will give them the key since I do trust them enough to perform illegal activities (at least knowingly) or eavesdrop on my traffic. However, they could technically. I came up with the extreme case where Eve would take an old smartphone, enter the key of Alice's network and charge that behind some furniture. It would record parts of the traffic (like DNS requests and passwords in HTTP) and sent it to some server. Alice would not notice this, and even if she finds the phone, Eve could say that she just forgot that she charged the phone there. Would setting up WPA2-Enterprise mitigate this sniffing problem, at least across the different identities?
I work as a tester at a VoIP software company. We've been running into a problem with using TLS to communicate with certain phones. The phones are from different manufacturers but both exhibit the same problem. To summarize as succinctly as I can, the phone is rejecting the certificate provided during SSL Handshake with "Unknown CA". The phones use versions of OpenSSL in their firmware, but I do not know which version. I have verified in every possible way that the Trusted CA certificate provided to the phone during provisioning and the certificate provided to the phone during the handshake are the same and match. Everything SHOULD be golden, however it isn't. What I've found is that on one system where everything is functioning properly, the CA cert provided has a 10 digit serial number and on the system where everything is not, the CA cert has a 12 digit serial number. It seems like such an arbitrary thing to be causing the rejection of the cert, but that is literally the ONLY difference I could find when comparing the working and not working systems and their certificates. Does this sound like something anyone has heard of before? Am I going crazy? Any and all help appreciated. --Edit-- Our PBX uses a self-signed CA Cert by default. It then uses that Cert to Sign a Line Cert (Server Cert) and also signs Certs used by the Phones (Client Cert). What appears to be happening is that when new Server Certs are generated, they're doing so w/ a 10-digit serial. I have the ability to use previously generated certificates (generated using the same methodology) that have 12-digit serials. When using the 12-digit Server Cert to complete the TLS Handshake, the phones accept the 12-digit CA cert. When using the 10-Digit Server Cert, the phones reject the 12-digit CA as "Unknown CA". This seems... completely arbitrary and wrong but it's what I've got. The new 10-digit certs are being generated using OpenSSL 1.0.1i. The 12-digit certs were being generated using an older version (0.9.7e I think). I doubt that matters much. One phone manufacturer uses OpenSSL 0.9.7e and the other uses OpenSSL 1.0.1c-fips
So I found an interesting method of remembering those pesky security questions. Basically, the guy takes a hash of the question (IE what is your mother's maiden name?) and then appends his own password (I assume it is unique for each hash). He claims this is a great way to always know the answer to your security questions without actually being truthful (some of those questions could be / used to be rather revealing) or knowing ahead of time which order they will be asked. For Example: Q: What is your mother's maiden name? A: dc6bae2bdc569b1ef118bf6a497c65a0e70fadaa653bfadabffe5519708fb538password where 'password' is actually a random and secure one (presumably stored in a password vault and specific to each question hash). Instead of: Q: What is your mother's maiden name? A: mommy Is this method really secure or just a waste of time? My question to him (and you guys) was why bother with the hash? Why not just keep a secure list of questions/passwords?
I understand that non repudiation intends to provide a mechanism that reliably proves that the sender of a message cannot deny sending the message. But does it also provide similar mechanisms to ensure the recipient of the message cannot deny receiving it.
I always thought it's possible to track attackers unless they try to hide their identities using some form of "physical" disguise. No matter how many proxies you use even TOR seems to be traceable by NSA but what about public WiFi networks? Anybody can simply go buy a used laptop from Sunday market (MAC cant be traced), sit next to McDonald's and fire their scripts? How is it possible to counter such simple but efficient arrangement?
I recently put a Linux server online and it didn't take long until I had the first attempts to brute-force the SSH login. It's not that I am worried about that - I trust the security of my server. But just out of boredom I looked up some of the originating IP addresses and noticed that almost all of them were Chinese. Why is it that so many cracking attempts originate from China? Does China provide an environment which is favorable for cybercrime to bloom? Or are we actually dealing with people from other countries who just like to use botnet zombies from China? In any case: The Chinese government is known for its ability to censor the internet access for their people. Why don't they use that infrastructure to shut down the criminal activity originating from their network?
Our system used to get bombarded by bots trying to login to the ssh client on the standard port. After switching to another port number the failed login attempts basically stopped completely. Recently, in the past week there has been a few unknown i.p. addresses attempting to login ( on average about 60 attempts a day) that appear to be on a few different networks coming from the same isp in china. I have no security experience, other than basic setup of clients and changing passwords etc. We are using logwatch to gather some information on the login attempts. What is the key information I will need about the attempts to analyze the situation and take action? What are basic steps to make sure we have not already been breached? What other actions I should take?
Aug 30 20:28:09 dropbear[6799]: Child connection from ::ffff:5.10.69.82:38463 Aug 30 20:28:11 dropbear[6799]: login attempt for nonexistent user from ::ffff:5.10.69.82:38463 Aug 30 20:28:12 dropbear[6799]: exit before auth: Disconnect received Aug 30 20:28:12 dropbear[6800]: Child connection from ::ffff:5.10.69.82:38805 I have MAC filtering and WPA2 security in place. Is this enough to protect my network?
Can anybody name all the risks of the following scenario: User visits a page, but his session is expired, so he is auto-redirected to login page with his previous page and params added as a single parameter, encoded using PHP's urlencode(): https;//www.example.com/login.php?previous_page=%2Fdashboard.php When logged in, autoredirect to: https;//www.example.com/dashboard.php I am currently aware of two: Manipulated links that contain external domain names, for example: https://www.example.com/login.php?previous_page=http%3A%2F%2Fxss.com%2Fmalware.php Manipulated links that contain scripts, for example: https://www.example.com/login.php?previous_page=%3Cscript%3Ealert(document.cookie)%3B%3C%2Fscript%3E Currently preventing these by only accepting the value of previous_page param if it starts with %2F (encoded /). Are there more risks to catch?

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