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I want to know how browsers detect phishing pages.And also what methodology browsers use to detect phishing pages?
I have below snapshot of log generated by auditd when I tried to delete a user. It doesn't have hostname and addr in the logs: type=DEL_USER msg=audit(1404811391.243:4407153): user pid=5772 uid=0 auid=513 ses=185589 msg='op=deleting user entries id=532 exe="/usr/sbin/userdel" hostname=? addr=? terminal=pts/1 res=success' My auditor wants that hostname and addr to be captured in logs when such administrative activity is performed. Also the date/timestamp is not in good format. Please suggest. I am pasting my auditd.conf file auditd.conf # # This file controls the configuration of the audit daemon # log_file = /var/log/audit/audit.log log_format = RAW log_group = root priority_boost = 4 flush = INCREMENTAL freq = 20 num_logs = 4 disp_qos = lossy dispatcher = /sbin/audispd name_format = none ##name = mydomain max_log_file = 5 max_log_file_action = ROTATE space_left = 75 space_left_action = SYSLOG action_mail_acct = root admin_space_left = 50 admin_space_left_action = SUSPEND disk_full_action = SUSPEND disk_error_action = SUSPEND ##tcp_listen_port = tcp_listen_queue = 5 tcp_max_per_addr = 1 ##tcp_client_ports = 1024-65535 tcp_client_max_idle = 0 enable_krb5 = no krb5_principal = auditd ##krb5_key_file = /etc/audit/audit.key
Consider this scenario Step 1: App asks user to "Sign In" using Google or Facebook. Step 2: Once authenticated, app sends user's Id (from Google/Facebook) to My App Server requested to app specific data Question Since the authentication is purely happening at the client level(iOS/ Android), there is no way for my server to know if user is a valid Google or Facebook user. The reason is that on the server if someone knows the API, they can easily play around with the system. How do I handle such scenarios to make sure the server has confidence over the user data coming from Google/Facebook? P.S: I am building a mobile application for the first time and this question may be a stupid one, but I don't know how to work with such a situation.
I set up my certificate for my mail server at https://mail.xxxx.com/ I exported my certificate as described in my mail servers documentation and pointed to it in the server settings. The certificate seems to validate 100% on all tests, even the issuer verified that all is well. However my mail clients like outlook and thunderbird seem to fail with invalid certificate warnings. You can see it fail at http://www.checktls.com/ if you use the email address support@xxxx.com [001.838] Certificate 1 of 3 in chain: subject= /OU=Domain Control Validated/OU=PositiveSSL/CN=mail.xxxx.com issuer= /C=GB/ST=Greater Manchester/L=Salford/O=COMODO CA Limited/CN=COMODO RSA Domain Validation Secure Server CA [001.886] Certificate 2 of 3 in chain: subject= /C=GB/ST=Greater Manchester/L=Salford/O=COMODO CA Limited/CN=COMODO RSA Domain Validation Secure Server CA issuer= /C=GB/ST=Greater Manchester/L=Salford/O=COMODO CA Limited/CN=COMODO RSA Certification Authority [001.933] Certificate 3 of 3 in chain: subject= /C=GB/ST=Greater Manchester/L=Salford/O=COMODO CA Limited/CN=COMODO RSA Domain Validation Secure Server CA issuer= /C=GB/ST=Greater Manchester/L=Salford/O=COMODO CA Limited/CN=COMODO RSA Certification Authority Validation Secure Server CA [003.400] Cert NOT VALIDATED: unable to get local issuer certificate [003.401] this may help: What Is An Intermediate Certificate [003.401] So email is encrypted but the domain is not verified [005.791] Cert Hostname VERIFIED (mail.xxxx.com = mail.xxxx.com) Edit : The chain moves to the second certificate but then repeats, and if i look at the chain anywhere else it connects fine. Im hoping someone can maybe shed light on what the problem is. Many thanks
I need to do some testing on boxed devices, incidentally having Bluetooth interface. I am quite sure that there are problems in the implementation, at least there must be given how the architecture has been developed. My question is: where can I find some theory on Bluetooth attacks? I am not happy only with BlueSnarfing or BlueJacking, or anyways 'old school' attacks. Any source of info is well accepted.
Since years ago, miscreants use JavaScript to craft web malware attacks such as drive-by download attack that is used for example to install the famous CoolWebSearch virus. There are static methods that analyze the text of web pages and teach a learning machine to inform a classifier how to detect web malware based on signatures. This approach is not good because it is useless against obfuscated JavaScript code and zero-day attacks. Other solutions exist and are based on the analysis of the dynamic behaviors of JavaScript using sandboxing environments or by setting a proxy (in both cases the page is not rendered for the user before its dynamic analysis). My question: Why do sandboxing environments used to supervise JavaScript malware not rely on an anti-virus program and prefer to use programs coded to scan the state of the machine (virtual machine) in which they run? (Antiviruses programs also use dynamix analysis)
I have recently started work in application security at a mid-sized firm, having transitioned away from 5+ years in security consulting (pentesting, etc). One of the biggest challenges I see here from the start are that security scanners and other tools use root/Administrator access, since that is what vendors had told them to use, most likely because of the ease of configuration. I really don't like this idea. For instance, Nexpose and Nessus are both configured to use root and Administrator. My question - What are the best practices in terms of governing access to these privileged accounts? My initial thought is to have a type of password-vault system, that solely knows the passwords to the system. Then, a user can "check out" the root/Administrator password as needed" For Nessus in particular, only a few commands are run as root, so I think it would make sense just to create a standard user, and add it to the sudoers file while only allowing those specific commands.
Say you have an ASP.NET page that lists the prices for certain items in labels. I know it's cringe-worthy, but say you took the price of the item from the label on the page to determine what the user is charged for their order. Does ASP.NET guarantee in any way that the text in those labels has not been tampered with?
I want to know if a firewall is considered an access control list (ACL). I know there are other types of ACLs, but am specifically interested in knowing if a firewall is an ACL. Edit: It appears from the answer below that the firewall itself is not an ACL, but are the rules for the firewall considered an ACL?
I was reading through RFC 5280, PKIX Certificate and CRL Profile, Section 4.2.1.6, Subject Alternative Name: The subject alternative name extension allows identities to be bound to the subject of the certificate. These identities may be included in addition to or in place of the identity in the subject field of the certificate. Defined options include an Internet electronic mail address, a DNS name, an IP address, and a Uniform Resource Identifier (URI). Other options exist, including completely local definitions. Question: how does one encode a username like "john" or "jdoe"? Here are the choices: GeneralName ::= CHOICE { otherName [0] OtherName, rfc822Name [1] IA5String, dNSName [2] IA5String, x400Address [3] ORAddress, directoryName [4] Name, ediPartyName [5] EDIPartyName, uniformResourceIdentifier [6] IA5String, iPAddress [7] OCTET STRING, registeredID [8] OBJECT IDENTIFIER } And I'm making a distinction between a PKCS #9 emailAddress ("jdoe@example.com") and a username ("jdoe").
Is it possible to unencrypted export a folder in KeepassX? I would like to share a part of my KeepassX database with a collegue but I have all of the needed passwords in separate entries in KeepassX
Is there a way to store a file on a disk as a user so that even the root user has no access to it? I tried EncFS but that is no solution because the root user can switch to every user, so he/she can read the encrypted files too. How can I store a file on the server so no-one can read it but me? Maybe somehow store it spread it redundant accross the unused diskspace and keep the inodes in mind to recover it via checksums?
I currently offer email subscriptions on my blog, something I coded myself in PHP. People sign up on the blog using their email address. I send them an email with a link to verify their email address and once verified, they get an email whenever a new post is published. I only publish about 4 or 5 posts in a month and every email sent has an unsubscribe link which unsubscribes them right away if they wish. I hate spam so I definitely don't want to send anyone email that they don't want. I'm constantly checking to see if any of the emails bounce (nothing does) and would remove them from the list right away if there was ever a problem. I'm presently not having any problem with the emails being delivered and as far as I know, they're not ending up in people's spam/junk folders. I've set up my VPS box with SPF and DKIM, SSL only, etc… I currently have just under 200 email subscribers. I'm wondering, is there any reason not to sign these subscription emails with an s/mime certificate? Would it improve deliverability? Or just give people the peace of mind of knowing that the email did in fact come from me? Also, what about for email receipts? I'm presently working on updating another site, which will have an e-commerce component to it (via Stripe), so I'll be sending a lot of email receipts (I hope!), and also an email newsletter through that site also. I know that s/mime is not that popular/wide-spread, so would sending these emails signed be a bad idea? (Not encrypted, just signed.) I don't see anyone else doing this, so I'm wondering if it's a bad idea? (Or why isn't anyone else doing it?)
Since I am new to encryption and have recently been losing stuff, I decided to start a file that contains some passwords for online accounts and whatnot, encrypt it, back it up (and keep a single copy on Google Drive....cloud storage seems insecure to me.) I was wondering about using GPG though. Is the default algorithm, CAST5, sufficient? gpg -c file uses it Is there any chance that my file could be broken by Google? It uses a long password that seems secure. Should I add extra information throughout to act as "additional entropy"? Maybe dd if=/dev/random >> file And the most important question...is GPG even right for this job-encrypting basic text files. Is there a better, mroe secure option, or a faster option?
am using apache 2.4.9 latest with windows 7 i am using some modules like limitipconn_module security2_module but using wireshark i get unlimited request to busy my webserver (DOS) from some ip address i have deny them and their ip ranges basicly on isp hostname but using proxies would be a new problem and i can not deny all ip address so other clients can not visit my website is there any method to block only ip address after 50 request per 10 seconds ? i have seen mod_evasive but it is not compatible with apache 2.4.9 or any idea for using firewall ?
From my iptables log, I can observe a particular remote IP address trying to connect to my server from port 80 to a private port number: Jul 09 01:24:41 example.com kernel: IPTABLES: IN=eth1 MAC=xx:xx:xx SRC=abc.a.b.c DST=xyz.x.y.z LEN=44 TOS=0x00 PREC=0x00 TTL=51 ID=16405 PROTO=TCP SPT=80 DPT=61412 WINDOW=16384 RES=0x00 ACK SYN URGP=0 Jul 09 01:29:42 example.com kernel: IPTABLES: IN=eth1 MAC=xx:xx:xx SRC=abc.a.b.c DST=xyz.x.y.z LEN=44 TOS=0x00 PREC=0x00 TTL=51 ID=31270 PROTO=TCP SPT=80 DPT=61412 WINDOW=16384 RES=0x00 ACK SYN URGP=0 Jul 09 01:32:41 example.com kernel: IPTABLES: IN=eth1 MAC=xx:xx:xx SRC=abc.a.b.c DST=xyz.x.y.z LEN=44 TOS=0x00 PREC=0x00 TTL=51 ID=43052 PROTO=TCP SPT=80 DPT=61412 WINDOW=16384 RES=0x00 ACK SYN URGP=0 Jul 09 01:34:40 example.com kernel: IPTABLES: IN=eth1 MAC=xx:xx:xx SRC=abc.a.b.c DST=xyz.x.y.z LEN=44 TOS=0x00 PREC=0x00 TTL=51 ID=53328 PROTO=TCP SPT=80 DPT=61412 WINDOW=16384 RES=0x00 ACK SYN URGP=0 This has been going on for a day and the connection is made every 5 minutes or so. I tried accessing the site from its IP address but it says connection reset. nslookup gives a non-authoritative answer: Non-authoritative answer: xyz.x.y.z.in-addr.arpa name = xyz.x.y.z.static.eigbox.net. It appears that someone could be spoofing my server's ip address, causing this remote computer to respond by sending ACK SYN packages to my server. I even log the iptables output to this IP address to ensure that my server is not responding to it. Is it possible to find out what a remote user is trying to do connecting to a closed port without compromising my server's security?
Click farms can be hired to boost ad revenue. http://www.security-faqs.com/what-is-a-click-farm.html The click farm is made up of armies of low paid workers who’s job is to click on links, surf around the target website for a period of time, perhaps signing up for newsletters and then to moving on to another link. It is very hard for an automated filter to analyse this simulated traffic and detect that is it invalid as it has exactly the same profile as a real site visitor. Google obviously tries to prevent click fraud. How long does it take (days, weeks, months) for Google to detect click fraud and terminate an AdSense account? Here is more info: https://webmasters.stackexchange.com/questions/66892/where-are-these-suspicious-traffic-sources-coming-from-that-i-see-in-google-anal Here are 2 examples side-by-side (top-to-bottom): https://i.stack.imgur.com/sLQNn.jpg
We modified our Session handling from cookie based to URL Rewriting. By doing this the session id gets transmitted as part of the URL. Now there is a vulnerability issue, where whoever uses this URL will be able to log in into the system. To resolve this issue we have done the following A HTTP Session Listener has been created to maintain list of HTTP sessions. Listener reacts on the events when session are created or destroyed. A Session Filter has been created to verify HTTP Session and check its integrity against HTTP Request attributes Session will be invalidated in case Request attributes (identifying the client origin) do not match original attributes stored with session. (to block the session hijack attempt) However i think that this has a gap, when you are trying to access over a proxy etc. Is there any other effective solution for this? Also we cannot use third party libraries to resolve this because of the nature of the produce.
I am making a web application in Django which generates and includes CSRF tokens for sessions (a Django session can be anonymous or a registered user). Should I keep CSRF protection to the controllers handling login and logout action?
I want to buy a Windows Phone 8 and a Blackberry (BB) device for practicing penetration testing of mobile applications (of course, Windows and BB apps). I am asking for appropriate devices. I don't want alternative of emulators please I have tried emulators concept but it does not suit well as is the case with Android devices. It is cumbersome to set up Windows emulators as my laptop does not meet the specifications. Can anyone suggest a good Windows as well as Blackberry phone that best suits for pentest of mobile apps?
A Paloalto firewall(PA-2050,POS 4.1x) was capable of recognizing the websites which users are visiting(thru http/https) then flag them with a App-ID and apply application control on the traffic, for instance blocking all webmail/file sharing/social media... etc. But PA-2050 can only recognize those traffic visiting websites with https as "SSL" after we setup a Squid proxy 3.4 with SSL bump before the firewall. This crippling the application control mechanism of PA firewall. Anyone knows how to config Squid 3.4 (or PA-2050) so as to recover the application control capability on https traffic thru Squid proxy?
First time doing a secure login from a mobile app to a server (built in java). I want to understand if I got this right. Login in for the first time: 1. On the mobile device hardcode a security phrase (ex: "superSecurePhrase@@!!". 2. Take in a username and password. 3. Use base64 to encode username+phrase and password+phrase. 4. Using https send this information to my server. 5. On the server decode using base64 with the matching phrase hardcoded on the device. 6. Hash password and save to DB, also hash username and save to DB. 7. Use AES algorithm to create a session token 8. Send session token to device. 9. Save session token to DB, and when user requests something, make sure they match. To verify credentials it is pretty much the same process except username and password aren't saved, but instead queried for the DB and checked for a match? Is this the general pattern used for this kind of thing? Potential vulnerabilities: 1. Physical access to the device to retrieve the hard coded base64 phrase? 2. SSL Sniffing and acquiring the token? Thank you for your help.
I am using few secret keys to encrypt sensible date. What is the best way/place to protect the keys ? In a file located on my server ? Within the SGBG databse itself ? Or ... ?
Say I have a QR-code on my laptop screen that I need to scan with my mobile device. Is there anything that can be done to make the on-screen code harder to scan from a distance? I am thinking for colors, contrast, movement, etc. At what point would the legit device have trouble scanning a, for example, moving QR code? Possibly ways of disguising the code in a photo or a noisy background? I would expect it would be harder to scan a rapidly clockwise movement from a distance than when you can fill the camera’s seeker with the code + wiggle-room. Any thoughts or other ideas? Throwing a blanket over my head and laptop while scanning the code would be more secure, but less practical than a software based solution.
My boss recently implemented a new security system related to PGP/GPG. The whole idea behind this is to sign files so that people know from who they came. They don't require us to encrypt them, just verify their authenticity. The problem is that wrapping my head around such new and complicated concepts is getting harder and harder. We're using GPA Kleopatra. So what I want to know: Say I want to send a person a file, I don't know that person, it could be anybody, it doesn't have to be encrypted, and I want him to know it came from me, is there anyway for me to do that? Again, no encryption, just authenticity verification. You don't have to explain it to me step by step, a tutorial on some site will do. But keep it simple and straight forward.
I have a web application I am doing a security assessment on and it uses captcha for both the login and for certain operations inside the app. The interesting thing is that this particular app displays the text of the captcha right under it (users complained, so...), so it would be feasible to rig something up to read the captcha text and use that, enabling the scan to be automated. Can anyone point to a resource that would help me script this? I use IBM appscan and Burp Suite. Without that text, though, I'm limited to hand testing. Would it be fair to say that these captcha makes the app immediately more secure because it is resistant to automated scans?
My understanding is that miners solve complex algorithms (sha256 i believe) and receive bitcoins. With the amount of hash power all these pools get from miners couldn't they use the resources to decrypt a bunch of encrypted information?
I want to learn sql injection, xss and other web attacks. I am new to all this, just a beginner. I want to know which software to use. Can I use Windows for these attacks and which software do I use? I came to know about some software like Nessus and Burp suite.
guys I am using Tor browser from some time, few weeks maybe and I am still trying to determine the level of anonymity that the browser gives. I am using the browser to advertise a service that I am offering in social networks. I create the accounts using outlook.com e-mail and since I am using Windows OS, I was wondering if outlook.com could get any information about my real identity when I am using their e-mail services. I am asking this because I have heard that if some company has a software installed on your computer, it can detect your MAC address. And what concerns me in particular is the fast that when I log into my outlook.com e-mail, it shows that I am active in Skype and Messenger. Since I never linked my skype account with the outlook.com account, they shouldn't have such kind of information right? So my question is - is there any chance that Microsoft and Outlook.com could have any kind of information about my true identity, I mean about the fact who uses the particular @outloo.com e-mail address and such? Is there any way for them to disclosure my true identity if the police asks them to? Such kind of things. Thanks in advance to anyone who would be kind enough to answer my question. Best regards, Cairien
So that: Only process owners, and root, can access information about their processes, Or, at the very least, cmdline permissions are only readable by root, and My system (CentOS 6.x) still runs Why do I care? I was just talking to a few developers who I think of as knowledgeable people, and only one out of the three of them knew that, by default, command line arguments for running programs are world-readable. Incidentally, the topic came up because I was mocking one of them (my brother) for passing a password via command line and he didn't get it, and now I'm worried idiots well meaning but misguided developers might have written programs I actually use, and my authentication tokens might be stupidly and wantonly passed via command line by some of the OSS I have running on my box. Extra credit If you could provide solutions for other *nix flavors that don't use /proc but do allow command-line listings (e.g. FreeBSD) , that would be much appreciated.
I have seen increased 'HEAD' requests in my webserver access.log. What are these requests for? Should I disable this method in my webserver configs?
I'm not at this point yet, thankfully, but being prepared means knowing the answer before the issue arises, so here goes... You're looking through your firewall / website logs... And you notice a large number of requests. Someone appears to have portscanned you, or run sqlmap or DirBuster, Nessus, metasploit or whatever. Apart from breaking out in cold sweat and making occult sacrifices to the Internet gods, what are good steps to take at this point? I'd assume you'd: go through other logs more carefully than usual, looking for derivations from the norm, (if it's only from one IP) do a reverse DNS query on them to see if they are associated with any domains, and, if they are, contact webmaster@, abuse@ and other RFC2142 addresses then, if they don't respond within 24 hours contact their ISP. (if it's from multiple IPs) check if they're using IPs from known anonymizing networks, and if they are, block those anonymizers (as much as possible). (if egregious enough / a clear attempt to break in or DOS, and not simply reconnaissance) contact the FBI (if any of the IPs are across state lines). Not sure what other law enforcement agencies you'd contact. Temporarily block ssh logins from non-essential users while the storm is being weathered (so your attack surface is smaller).
Yes. Of course using https everywhere is best. But sometimes that's not an option. In those cases, I'd like to make an informed decision. Is there any information about their prevalence? Or would that all be hidden anyway so no one knows? Does it depend on the site visited? To be clear: I'm not referring to an attack on my wifi connection. Nor any other kind of attack. I'm asking specifically about connecting to a major ISP (let's assume U.S.) and visiting a site or connecting to my hosted web site. I'm also not asking about the government being the mitm, just anybody else.
If I am trying to destroy a single file, what is the best method? shred -uvz -n500 file dd if=/dev/null of=file dd if=/dev/zero of=file I hexdumped a file that was in the middle of shredding, and it was appropriately mangled with what shred said it was writing, but is it secure? For the sake of this experiment, let's assume any cached versions of this file and anything else that may connect to this file are completely gone. The only remaining trace of the file is the command ran from my history...
I have recently been reading about the DRM measures on commercial bluray disks, in particular BD+. It seems that this technology involves Java software running in a virtual machine, with full access to physical hardware and the ability to run native code. This appears to be the case for standalone bluray players, but what about if I watch a bluray disc on my Windows PC (e.g. with Cyberlink PowerDVD). Does the software on the bluray get full administrator access to my system? This seems like a horrible security risk (I would never like to run anything Java-based as root). Can anyone tell me more about how BD+ protection works, in particular when watching on computers? What are the security implications?
I want to make my email address available on my website and I was wondering if there was any point in using the "(at) (dot)" convention these days. If I was writing a script to trawl for email addresses it would definite contain a match criterion for this. Similarly, for the same reasons it seems unlikely that using the html unicode version of my email would actually be an effective protection. It seems like it wouldn't be worth the inconvenience of not providing an actual link (and not being able to use an image). The different ways of writing email addresses seem like security though obscurity, but not obscure at all. So, will using the "(at) (dot)" convention actually affect whether people get my email address? Will modern spam filters make the answer to (1) irrelevant?
I was stumbling around and happened onto this essay by Bruce Schneier claiming that the XKCD password scheme was effectively dead. Modern password crackers combine different words from their dictionaries: [...] This is why the oft-cited XKCD scheme for generating passwords -- string together individual words like "correcthorsebatterystaple" -- is no longer good advice. The password crackers are on to this trick. The attacker will feed any personal information he has access to about the password creator into the password crackers. A good password cracker will test names and addresses from the address book, meaningful dates, and any other personal information it has. [...] if your program ever stored it in memory, this process will grab it. His contention seems to be that because it's known that people might construct their passwords in such a way that it makes it amenable to attack, but it seems like the strength lies purely in the power of exponents. I assume he's alluding to people not choosing the words truly randomly, which perhaps isn't totally disingenuous, as I've rerolled a couple times to get something that isn't all adverbs and adjectives. However, I assume that lowering the entropy by a factor of 2-10 isn't really significant (if the word list is doubled to 4000, not that hard, the loss is more than recovered). The other quip about "if your program ever stored it in memory" is a bit disconcerting though...aren't all passwords stored in memory at one time or another? That seems a bit overbroad; what is he actually referring to?
There are some people saying that people should use an antivirus software on Mac. And there are thousands of people claiming that Macs don't get viruses (under this term I mean spyware / malware as well), some even say that it's just a trick from antivirus companies to say that there is a need for antivirus. Honestly, I'm a bit confused. I don't want to waste resources on a possible unnecessary antivirus software, but I want to have my computer safe. If it's common knowledge that Macs don't get viruses for quite some years now, shouldn't there be some bad people thriving to prove this wrong? ( Edit, here is a quite recent reference on people dismissing antivirus softwares on mac: https://discussions.apple.com/message/24714586. )
I wonder what are the main registry windows keys malware target often ? I would love to code a program that will check the state of those windows registry keys for eventual modifications by malware.
A few days ago I was searching YouTube and I noticed an "outlier" video poped up in the suggestions list. This video had nothing to do with the topic being searched, but instead it was based on a previous search that was requested from this same computer two weeks ago. This was impressive considering the situation difficulted fingerprinting. In particular: I was not logged, nor was any other person in this machine, to YouTube nor any other Google service. The browser is configured in "private" mode by default, so every cookie/storage/websql/indexeddb file is deleted when it is closed. This means whatever info they stored was backed up online. The IP changes at least once each day, so hundreds or thousands of IPs would be associated with this geographical area. I'm almost sure they can only pin it down to the city level for what I have been able to observe in Gmail's account activity page for several users in this same area. The user agent is nothing out of the common, as the browser regularly updates to the last version. In fact, this is not 100% verified but I'm pretty sure their profiling method is somehow resistant to IP and user agent changes. Installed plugins are the usual ones, very common as well. Same about installed fonts and screen resolution. In fact there are more computers in the LAN with almost the same setup (OS/browser/plugins). And they share the same IP. How were they able to identify the correct one over a two weeks period of time beats me. Only disabling scripts for the google.com domain solved it, at the expense of not being able to read the comments. I've visited panopticlick's site and nothing shown in the table is unique to the point of tracking an individual user over time. However the page says the fingerprint is unique among 4 million, which is a number greater than the population of the geographical area (also in the order of millions). Questions: Is there anything in the browser unique enough to identify a machine inside a large city, or is it the combination of several characteristics what makes identification possible? Are Google's fingerprinting methods known? Has anyone conducted an analysis of their scripts?
On Windows (XP, 7, 8, NT ...): can .dll files be modified (in any manner) by benign programs/software already installed/running on the computer ?
I want to built some short urls for uploaded files and links on my own server. Simple enough, I upload files and my script returns me a link. On access, the link is translated to the file and download starts. Because it's modern, I want my links short and not so UUID4-like, because they are very long. I do not want that someone tries a few URLs to found a valid link. Maybe I should sent only 404's if an IP already had 10 wrong urls called? To built short random strings I thinking about the following: Prefill a SQL-Table (key, target) where key is case sensitive with all possible values in a defined range like [a-zA-Z0-9_-~=]{12}. Then select with WHERE target IS NULL ORDER BY RANDOM() an empty key and use it. This will guarantee I never generate the same key twice but needs a lot of storage and may be too much. I generate an UUID4-string and throw an hash-algorithm like SHA3 over it and use the first 12 characters of the result. Then I try to insert this in my table. If this fails, I need to generate an new UUID4 and so on... Of course, these are very theoretical thoughts, because I think I will be fine with 1000 keys per year. But how shortening url services do this? Or they don't care about "unpredictableness"?
In an authentication protocol, S has a public/private key pair known to C, and S and C have established a secure channel (for example, using DH or ECDH, or any other key exchange protocol). C wishes to determine whether the peer over this secure channel possesses the private key. In ECDSA, the key pair is an elliptic curve key pair, and the signature algorithm uses the DSA scheme (DSS) with the elliptic curve. The DSA scheme is known to have some undesirable properties -- weaknesses in the RNG are a real concern, considering that an attacker can obtain a million signatures. If authentication only is required, we don't need a fully-blown signature scheme (ie, the ability to sign arbitrary messages is not required). What alternative schemes could be used which avoid the scary property that re-use of the identification key in multiple signatures will eventually leak it? One simple scheme follows: C uses IES to encrypt a nonce N1, and sends this to S (this is the elliptic curve integrated encryption scheme). S then sends HMAC(key=Z, N1) back to the C, where Z is a shared secret obtained via the key exchange phase (remember, we've already established a shared channel using DH or some other method). This proves possession of the private key: the private key is required for S to have obtained N1 from EIS(N1). The server is not a decryption oracle -- it doesn't decrypt arbitrary messages on behalf of C, but rather replies with the HMAC of the decrypted value. Finally, because the shared secret Z was mixed in, which was jointly determined by C and S, the signature can't be used to perform a man in the middle attack: someone wishing to impersonate S to C is sent by C the encrypted N1, but can't forward it to S for signing, because the signature is tied to the channel's Z. Question Does my dead-simple scheme have a name? Is it weak? It appears to avoid the DSA problem where multiple signatures may eventually reveal the key, but I haven't done all the algebra to be sure! What are the popular standard solutions to the problem? FHMQV is patented, sadly, but it's designed exactly for this situation, isn't it. I guess the popular solution appears to be ECDSA (used in TLS, SSH), which I'd hope to avoid. Remarks Menezes' article "elliptic curve signature schemes" in the "Encyclopedia of Cryptography and Security" lists DSA, Schnorr, Nyberg-Rueppel as the various known elliptic curve signature schemes. DSA is the one I don't like, and Nyberg-Rueppel apparently has exactly the same weakness as DSA (two signatures using nonces with any known bits in common leak private key information). Schnorr signatures look good, but they don't seem to be widely used. Hugo Krawczyk's HCR (Hashed Challenge-Response, based on XCR, Exponential Challenge-Response) looks very promising too -- it's a beefed-up version of Schnorr that is supposed to be more robust. I think it's covered by Patent EP1847062B1 though, which expires around 2025 apparently.
I have some HDDs which are encrypted to what I think is a decent standard. I want to lock these away in a remote storage facility, but am a little worried about EMP/Magnetic stuff from wiping the HDDs. I will be backing up the HDDs, but wanted to know if there is cheap easy way to protect the HDDs from EMP/Magnets from wiping the information on them?
One of my friend challenged me that if my laptop is turned on then he can attach a device to it, just like in movies which will copy all data of my computer to his hard drive without touching a single key on my laptop. My question is that is it possible and even if he gets data from hard-drive can he decode it, and then are there gadgets already there or is it just Film thing... and he is chatting bubbles. Edit My laptop is not encrypted with bit locker, but if I do add bit locker, would it be secure enough then ?
I am a CS student, and am considering competing in the National Collegiate Cyber Defense Competition. Although I have a fair amount of experience in programming competitions (e.g. ACM at High School level, and various online competitions), I have never really considered information security competitions and/or study. Question: Starting from nearly ground-zero in information security and networking, how should one prepare for playing "blue team" in a competition like the CCDC? Specifically, is there a "THE book" that would be useful to read? (For an example, it is generally considered that Introduction to Algorithms by CLRS and The Art of Computer Programming by Knuth are definitive works for algorithm analysis. Also, The C Programming Language by K&R is the definitive work on C. Is there an analog for computer security?) Note: I realize this may be closed as subjective (or similar), but I really think a question like this would add value (if not Google hits) to the site. I figure I'll give it a try and see what the community thinks.
I am redirecting URLs to a virtual machine (Windows operating system) to check if there is malware on the website i want to visit (JavaScript attacks, drive-by download attacks, infected pictures/PDF files or executables embedded on the webpages ...). In the case there is a webmalware embedded on one of the webpages: what aspects of the virtual machine must I check for eventual changes done by the webmlware ?
I'm developing a kind of standard web-application, to be hosted internally on few customer's servers (not a public service, startup or anything like that). A kind of CMS, e-learning platform or something close to that. Because this is an internal project, customer had given me quite a large decision field and did not specified problem in question. My developed web-application is planned to have few admins and only one superuser per each installation. In this case, should application logs be available to admin-level users or strictly prohibited to be viewed by superuser only?
I know that there are already tools out there to generate cryptographic random number, but I was wondering if using AES could do the same. For example, I have a secret key for AES on my server and a counter in my database. Each time I want to generate a random number I increment the counter then encrypt it with AES using the secret key on my server then transform the resulting bits into the right number. Wouldn't this produce secure random number as long as my secret key is not found? N.B.: If you want to say that storing a password on your server is not safe, please explain how it is different than storing your private SSL key on your server. Edit Found some info on wikipedia A secure block cipher can be converted into a CSPRNG by running it in counter mode. This is done by choosing a random key and encrypting a 0, then encrypting a 1, then encrypting a 2, etc. The counter can also be started at an arbitrary number other than zero. Obviously, the period will be 2n for an n-bit block cipher; equally obviously, the initial values (i.e., key and "plaintext") must not become known to an attacker, however good this CSPRNG construction might be. Otherwise, all security will be lost. So, it was used before to construct CSPRNG.
My Exchange Admin is setting up 2013, and it is set to block txt file attachments specifically (as well as others). I have tried searching for risks associated with txt attachments but could not find any. Are there any risks I need to be aware of surrounding txt attachments? EDIT The Admin did not set up the rules for blocking, but found that this was the default rule for Exchange 2013 during a migration from 2010. It was causing problems in our environment, so he asked me to approve the whitelisting of .txt files.
Within the last week, I've received 3 phone calls at 3 different locations from technicians who are calling "from Microsoft" about "Windows problems" that they've detected on my PC. Which they haven't because scam. And it was only good luck that I was visiting my parents when they called them. I've since warned them to just hang up on anyone who tries that. I'm in the United States. I'm on the do not call list. The phone calls come from an unidentifiable phone number. The voices on the other line have been heavily accented, reminiscent of someone from a call center in India. I've seen this video of someone completely awesome running one of these guys through a honeypot. I'm technically inclined, and I'm tempted to create my own virtual garbage environment for them to screw with and try to hijack, but it might be more effort than I am capable of putting out. Other than requesting the caller perform deviant acts upon himself and his family, then hanging up, is there anything technical I can do, or report? Is there a fake honeypot website I can use to simulate what he's looking for to waste his time and perhaps backtrack him? How should I handle this for maximum impact against the caller?
An organization requires employees to use 2 person authentication in some scenarios. That is, when accessing, say, a server, secret knowledge from 2 people should be used for authentication. No one person should ever have access to the server alone. Question: What implementations of this requirement are possible? This is a Windows setup. The only implementation I can think of is the following: 2 people both connect to the machine (say, remotely), first person enters first part of the password he knows, and the second person enters the second half. Note: Not to be confused with two factor authentication.
From what I understand, the JSON-P technique generates a script tag into the DOM of an HTML page to get across the single-origin restrictions imposed on the XMLHttpRequest JavaScript API for AJAX calls to web services not supporting CORS. Usually, the script embedded in this way only contains a callback and in this way transfers the JSON payload that I'm interested in. However, AFAIK the called JSON-P service could also deliver arbitrary JavaScript and in this way hijack my webpage. I'm wondering if I really have to trust the JSON-P service provider not to do this? Or do JavaScript libraries and/or browsers sanitize the JSON-P responses and in this way prevent these kind of attacks? For example for the JQuery ajax function, the use of JSON-P is enabled by setting the rather harmlessly looking attribute dataType: 'jsonp' - so maybe these kind of calls are not as bad as I think they are?
When interaction between the user and the operating system is too slow (Windows become slow in responding to different user's request): what parameters could we check (and that we could use within a program coded in any programming language) in order to say for sure that the computer running this Windows operating system is maybe infected?
I have been using GUIDs as un-guessable tokens in various situations for some time. I came across this question/answer which seems to suggest that while this is ok in some situations, it should not be done where security is a significant concern. Typically when I am trying to understand a vulnerability, I will create an application on my test environment which reproduces the vulnerability and I can then exploit it to see how it works in the real world. Can anyone point me to any resources that go over how a GUID that is being used as an un-guessable token could be guessed in a controlled environment?
Or are certs both host- and port-specific (excepting wildcard certs)? I would assume they aren't, because they're supposed to verify a domain, but at the same time I've never seen anyone run HTTPS on any port other than 443, and I've only seen X.509 certs used in conjunction with HTTPS, so despite the fact that the answer is probably "no", I wanted to check.
When a system is suspected to be infected, one of the measures often recommended for cleaning the system (without actually taking the "nuke from orbit" approach) is to scan the drive with anti-malware tools from a known-trustworthy system. The way this is normally accomplished is by removing the drive from the suspect system, and attaching it externally or internally (as a non-system drive) to the trusted system. However, an alternative option in theory would be to scan the suspect system over the network. For example, on a Windows system, an Administrator can read the entire contents of the system drive via the built-in share \\hostname\C$. A networked drive mapping can be made from the trusted system to the suspect system's C$ share, and then antimalware programs can be run against the mapped drive. Is a remote file system scan in this way equivalent in effectiveness to an offline scan of the drive? Or, since the suspect system's OS is still running, are there common ways that rootkits can still hide their presence from the system being used for scanning over the network which would not be possible if the suspect system was actually offline? Obviously, "nuke from orbit" is, as they say, "the only way to be sure". However, that option is not in-scope for this question. I'm only asking if a remote scan of a file system is just as effective against rootkits as an actual offline scan of the same system.
There are some optional cases in SSL/TLS where server can demand the certificate of the client. Can anyone give me any example regarding this? Thank you.
Imagine you have a private RSA-key on your computer encrypted (through PBKDF2, AES-CTR, HMAC256) with a password, now if the user would like to tick "Remember Password", what is the most secure way to save/remembmer the password? Obviously it's not storing it in plaintext in the local directory. One option would be to use: the HardwareID of the computer the SID of the current user the windows built-in EncryptFile (needs to be logged in as the same account) Problem is that all of those informations can be compromised when you use the Utilman.exe Trick for example. An alternative would be obfuscation, but we know that isn't really a solution for the long term. Is there a proper solution for this or is this just bad practice?
I have a PGP signature of a known message. However, I am not sure who signed it. Can I get the public key - or, at least, the fingerprint/other way of searching for it on a public keyserver - just from the message and a signature? Example: I have this message/signature from here https://futureboy.us/pgp.html -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I vote YES on this important measure. Alan Eliasen -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) iEYEARECAAYFAlHZCvgACgkQ5IGEtbBWdrF5HgCfc4xhT29ouAWdo1PMlyDKIfaq pGoAoKig5sCXukrPPoKC1ZYB5CW7BzNL =WPPL -----END PGP SIGNATURE----- Can I somehow find who signed it, just by looking at it?
I read the question about the relevancy of the xkcd password creation algorithm. Would it be more secure if you used a string of common words with a function that only you knew that would rearrange the characters of said common words? Define a string of common words and a function f that rearranges the characters in the string in a pattern. Then let your password = f(string). Using the xkcd password as the starting string: correcthorsebatterystaple. f = rewrite correcthorsebatterystaple in a seemingly random but logical way. So f(correcthorsebatterystaple) could become something like csbthaapolteotrerrryseect Would this have a greater level of security? What if you allowed f to be any kind of transformation including transformations that added new information?
There are a bunch of people in the anti-surveillance movement who are virtually demanding that I enable SMTP STARTTLS support in my environment, in order to enable opportunistic MTA-to-MTA encryption. The same anti-surveillance people are meanwhile complaining that OpenSSL is poor-quality code with a high likelihood of severe undiscovered vulnerabilities. Is exposing OpenSSL (most MTAs including ours only support OpenSSL) to the Internet a worthwhile risk, for the benefit of opportunistically preventing eavesdropping? It seems like the risk of people eavesdropping on email in transit pales in comparison to the risk of OpenSSL being exploited on the mail server to steal stored data or install a persistent back door.
Is there any need to penetration test a GoogleAppEngine solution? Or will it be protected by googles existing infrastructure?
I am about to push hard against the powers that be and strongly recommend that we shift our many (20+) consultants from direct public access to RDP & SSH to VPN clients (connecting to a VLAN/subnet that has restricted access to only necessary resources). Given that we have a third-party SOC managing an IDS and monitoring connections, what are the risks of exposing RDP and SSH to the internet that forcing remote access via VPN will solve?
I have created a REST api, and now i'm thinking about authentication. I want the mobile application's flow for the user to be very simple: only having to enter a username and then this username together with 'some password' will be used to authenticate the user on every api call (using header fields, over SSL). Is this a good way to authenticate the user with as little trouble for the user as possible? I believe whatsapp used a similar approach, using the device's MAC-address as the password, and let the user enter his phone number as username. I've also once read some critique on this approach, but if this is so bad, what is a better way of doing it? So basically what i'm looking for is a way to do authentication with as little user input as possible (only a username), with at max one account per device, but for it to still be secure for calls to my api. Is there such an approach, if so, how would it go?
On my website I have a password reset page that users can use if they have forgotten their password. On this page they can enter their username or their email address and hit "reset" which will send them a link to reset their password. If they have entered an incorrect username or email, should I let them know that it does not exist in our system, or is that a security risk?
I'd like to know if giving access to Intel version of /dev/kvm on Linux to a user that just wants to spawn VMs gives him any extra privileges. That is, are her VMs subject to process scheduling just like other processes? Does it automatically grant direct access to any devices or memory?
Sorry for this stupid question but i'm thinking about what an attacker can do with a non persistent XSS attack on a website? An attacker can try to phish me with a malicious url, steal my cookies or my history etc... but does he also need my intervention or a human interaction for his attack? What else he can do with non persistent XSS?
One of my colleagues is working on securing OAuth 2 client IDs and secrets for our OAuth server and he has come up with this scheme where he would not only use UUID v4 to generate random values, but also bcrypt them. Another colleague asked what's the purpose of bcrypt-ing them, to which he got the answer that just UUID v4 "loses 4 bits of randomness" (which would make the generated values more guessable). The question seemed legit as far as my knowledge goes, but I couldn't find anything about the "loses 4 bits of randomness" part. My question is if the usage of bcrypt here actually has an added benefit and, if so, how much added benefit. I'm not very knowledgeable when it comes to cryptography, ciphers, crypto-secure random numbers and so on, so pointers to further reading related to this particular question would be appreciated.
let me explain my problem. The wifi on my macbook suddenly stopped working so tried to use my usb wifi adapter on a linux VM. But the funny thing is that nothing works on the guest vm either... Well funny thing because, I get an IP from my DHCP and I can connect to the internet, but only to google's websites! exemple: ping google.com = ok and ping bing.com = nok . Obviously, the rest of my network is working fine and I only get issues on this particular mac. Can something affect my host file or something like that on OSX and affect my linux as well ? Have you ever seen such malware? I got pirated several before!
I'm currently building an authentication module and I've got a question. I have set up a server with an API and want my users to authenticate to this server, but I use AngularJS for the site. Everything with AngularJS is client side, so I was wondering how to set the user ID without anyone being able to just change it and pretend they're someone else. The way I'm thinking of doing this is that when a user logs in on my app, I create a random string on my server and hash it. I then send it to the app and store it both in the app's local storage and in the database on my server, and I have the app include it with all requests. This way, when someone makes a request I can just check that string they send is the one in my database; when a user logs out, I clear local storage and remove the string from my database. I create a new string when they next log in. Is this a good idea? Maybe this is the normal way to go, but I couldn't find any free authentication solutions on the Internet. Since this app will probably have a lot of traffic, I'm not willing to pay for every connection to my server.
Honesty commands me straight away to say that I'm not a professional, but I'm fascinated by data encryption. This algorithm won't be used in production code, so please don't flood me with "Don't design your own crypto", I know. I apologise in advance if the question is unfit for this site. I was wondering how secure the following encryption algorithm would be. It would take: a 256-bytes long key, to be interpreted as a series of numbers. data to be encrypted, read in 256-bytes long blocks. The key is such that no two values are repeated, and all values should be in the 0x00–0xFF range. This means there's 256! possible combinations, if I'm not wrong. Yet, some of those combinations are more entropic than others – which makes some of them less useful, right? Now, a copy of the data chunk is made, and the key is iterated on. The first byte in the original data chunk is moved to the first value in the key; the second, to the second value in the key, and so on. In pseudocode: for index, destination in enumerate(key): data_enc[destination] = data[index] Not being a substitution cipher, it should be harder to guess which value is which. Yet, I am aware that the substitution is always the same throughout the data, so that surely counts as a weakness. The main weakness is its simplicity, I suppose. What do you think?
I'd like to show a CAPTCHA to prevent brute forcing attempts, but I was thinking of showing it whenever a user fails for an invalid username/password combination after X attempts, regardless of whether that user exists in the database or not. The thought was that if a user did exist, then all an attacker would have to do is record which username combinations (after X attempts) displayed CAPTCHA vs did not (and thus based upon that, I can get all of the e-mails out of the database). So therefore I'd show the captcha after x attempts regardless. now, to keep track of that, I guess I'd need a database table that literally saves whatever input the user typed in, but does that seem somewhat excessive? that someone could try test@test.com in one country, and in another, etc, and then one person ruins it for everyone to see captcha. I could also try it by test@test.com + IP address (so only if you tried X times with a bad username/password combo from your current IP that it would show the CAPTCHA). Do you think I should store IP ADDRESS and use that as the basis of showing a CAPTCHA for an invalid username/password combo? Or should I simply stick to the text used universally for some period of time. Thanks!
I want to develop a system, something like a comment system for a website, that ensures I know who is posting comments. The content that is exchanged is not valuable and does not need to be encrypted, I just want to have a some reasonable assurance that the person posting the comment is in fact who they say they are. If a post is spam for example, I want to be able to hold the person accountable. At the same time I need the system to be low overhead for users. For example giving them a list of 100 one time phrases that would have to be pasted into an email or onto a website would be acceptable. I am using node.js and was considering using a diffie-hellman key-exchange. I know this is fuzzy and I'm not looking for answers per se, but rather a way to think about it, an example or starting point or ... ? Edit #1 Thanks for the intelligent questions and thoughts. Use case: Someone physically comes to me and with a thumb drive and I give them a set of one time ciphers. [206,99087,3,etc]. And yes, they have to agree to give me some information and be physically identified. Each time they comment or post (and perhaps post through email) I want one of those ciphers to be sent to me, and they are not reusable. When my application gets an email or a posted comment there is a high degree of certainty about the identity of the person. Little is at stake besides "reputation" so there is little incentive to break into the system, but it shouldn't be trivial. Accountability means their reputation suffers or they are banned from using the application. Since this is based on their physical person rather than their disposable email person this is sufficient.
I wrote a simple system with SP-initiating Web SSO scenario based on OIOSAML. To test the system, I deployed it on the remote host. However AssertionConsumerServiceURL, where I specified URL, on which Shibboleth idP (idP based on Shibboleth) should return the answer is not called. SAMLAssertionConsumer - just a simple Java servlet. For a begin with, I just need to make sure that the response comes. Generated AuthnRequest: <?xml version="1.0" encoding="UTF-8"?> <saml2p:AuthnRequest xmlns:saml2p="urn:oasis:names:tc:SAML:2.0:protocol" AssertionConsumerServiceURL="http://ip-of-remote-system-here:8080/saml/consumer" Destination="http://ip-of-identity-provider-here/idp/profile/SAML2/Redirect/SSO" ForceAuthn="false" ID="_068712cd-......163720312" IsPassive="false" IssueInstant="2014-07-12T06:42:16.673Z" ProtocolBinding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" Version="2.0"> <saml2:Issuer xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">http://ip-of-remote-system-here:8080</saml2:Issuer> </saml2p:AuthnRequest> if I make request to my servlet SAMLAssertionConsumer direct: http://ip-of-remote-system-here:8080/saml/consumer Then it works. I would like to know how to properly configure the the assertion consumer service. That is the part of the SP-metadata, where I specify the assertion consumer. <?xml version="1.0" encoding="UTF-8"?> <md:EntityDescriptor xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata" xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" xmlns:esia="urn:esia:shibboleth:2.0:mdext" entityID="http://ip-of-remote-system-here:8080"> <md:SPSSODescriptor AuthnRequestsSigned="true" WantAssertionsSigned="true" protocolSupportEnumeration="urn:oasis:names:tc:SAML:2.0:protocol"> <md:KeyDescriptor use="signing"> <ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#"> <ds:X509Data> <ds:X509Certificate> MIID...XY7ZiQ== </ds:X509Certificate> </ds:X509Data> </ds:KeyInfo> </md:KeyDescriptor> <md:KeyDescriptor use="encryption"> <ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#"> <ds:X509Data> <ds:X509Certificate> MIID...XY7ZiQ== </ds:X509Certificate> </ds:X509Data> </ds:KeyInfo> </md:KeyDescriptor> <md:SingleLogoutService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect" Location="http://ip-of-remote-system-here:8080/saml/consumer" ResponseLocation="http://ip-of-remote-system-here:8080/saml/consumer"/> <md:AssertionConsumerService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" Location="http://ip-of-remote-system-here:8080/saml/consumer" index="0" isDefault="true"/> </md:SPSSODescriptor> <md:AttributeAuthorityDescriptor protocolSupportEnumeration="urn:oasis:names:tc:SAML:1.1:protocol urn:oasis:names:tc:SAML:2.0:protocol"> ... </md:AttributeAuthorityDescriptor> <md:Organization> ... </md:Organization> <md:ContactPerson contactType="technical"> ... </md:ContactPerson> <md:Extensions> ... </md:Extensions> </md:EntityDescriptor> I would be very grateful for the information. Thanks to all.
My antivirus picked up an infection by Dialer/Coulomb. The definition of a dialer is a piece of malware that dials a number that charges money. How would it do this, is this from when modems were connected to the phone lines? Can this still happen if the computer is connected through wi-fi to a cable modem?
I am able to inject this: http://domain.com/search/songs/<img src='alert(document.cookie)' onerror='alert(document.cookie)'> to the page HTML. The onerror event is giving me the cookie on my latest updated Firefox. But Chrome is sanitizing the HTML to this: <img src="alert(document.cookie)" onerror=""> When I try to inject the script tag, the application is somehow sanitizing it. I dont know if I should share the website on which I found this vulnerability here. Please suggest me on how to make it work on Chrome.
When you find a vulnerability, do you contact CVE assigners before contacting the vendor or after the vendor has fixed the problem? PS: do not link to How are CVE identifiers assigned and managed?, as it doesn't answer my question.
Is it possible to implement MITM attack on larger networks than LAN? For example is is possible to implement such an attack on the whole network of an ISP?
I want to make sure each of my apps users only get their own data, and that nobody tampers with it or sniffs it in a MITM fashion. Encryption of everything should be the solution, right? But how do I distribute the keys? Afaik SSL/TLS only makes sure the client is talking to the correct server, not the other way around. I want to make sure the client is who it says to be. I thought of using asymmetric encryption to solve this. The servers public key could be included in the app, and distributed through app store/google play. Then the user would be able to talk to the server securely from the start. The client can then send it's public key securely to the server, allowing two way encrypted communication, and making sure the server is sending the data to the correct client. All of this would then be sent over https. Am I over-complicating this? What security holes am I missing? Is there something else I would need to make this secure? I don't want to reinvent the wheel, so an existing solution would be preferred.
I've read that the answer has something to do Socialist Millionaire, but I still don't understand how can the user be protected against malicious Man In The Middle, which would capture the question and answer by itself if it knows the answer. Could anyone explain that to me how can we authenticate someone getting his key from a secure channel?
Can anyone please give me a quick crash course on SSH and GPG? SSH: What is the difference between public and private keys? Should I back up my ~/.ssh/ directory, what are the security implications of doing so? GPG: Again, difference between public and private keys. What is an effective way to use GPG? Encrypt a text file containing information and then...what happens after that? Is CAST5 (GPG default, I believe) secure? If I don't use gpg -c file it starts asking for users. What is this? What do I enter here? Are there any official security.stackexchange.com threads on learning security like this? Are there any one security in general, including not just this but maybe networking and cryptography and other things?
I'm a tired of these stupid scammers trying to rip off fellow university students desperate for housing, so as for some free time activity I thought I'd try and do some scam baiting, and send him to MoneyGram and Western Union a few times in vain for the fun of it :) I will use a free online gmx account for the email. I will create a fake name and cover story. Questions: I have never really used a service like tor, but is this necessary to ensure my protection? Is this sort of information encoded in metadata? I could also use one of the university computers, would this help? Are there any other precautions I should take?
I have a Debian 7 VPS that runs Nginx, PHP5-FPM and MariaDB. This server runs a couple of WordPress installations, phpMyAdmin and Roundcube Webmail. One is my personal blog running WP 3.9.1 and another runs the latest WP trunk version 4.0-beta1 for development purposes. I am the only person to have SSH access as well as wp-admin access. Root login via SSH is disabled and so is logging in using passwords. Today I found the following files inside /tmp. # ls -l /tmp total 8 -rw------- 1 www-data www-data 1551 Jul 9 03:22 php9Lg8Js -rw------- 1 www-data www-data 1551 Jul 9 03:23 phpQNsW36 stat output for the files # stat /tmp/phpQNsW36 File: `/tmp/phpQNsW36' Size: 1551 Blocks: 8 IO Block: 4096 regular file Device: ca01h/51713d Inode: 337356 Links: 1 Access: (0600/-rw-------) Uid: ( 33/www-data) Gid: ( 33/www-data) Access: 2014-07-09 03:23:03.000000000 +0530 Modify: 2014-07-09 03:23:03.000000000 +0530 Change: 2014-07-09 03:23:03.000000000 +0530 Birth: - # stat /tmp/php9Lg8Js File: `/tmp/php9Lg8Js' Size: 1551 Blocks: 8 IO Block: 4096 regular file Device: ca01h/51713d Inode: 337355 Links: 1 Access: (0600/-rw-------) Uid: ( 33/www-data) Gid: ( 33/www-data) Access: 2014-07-09 03:22:27.000000000 +0530 Modify: 2014-07-09 03:22:27.000000000 +0530 Change: 2014-07-09 03:22:27.000000000 +0530 Birth: - Both these files contain the same base64 encoded PHP code. I replaced the eval() with print() to find it was a PHP shellcode which emails the HTTP_HOST and REQUEST_URI to two Gmail addresses as well as prints an input box for the exploiter to run shell commands and upload files. I can post this code here if it required for analysis and if I am allowed to do so. Searching the Nginx access log based on the timestamp I could only find the following POST requests. 121.97.137.10 - - [09/Jul/2014:03:22:27 +0530] "POST /index.php?option=com_jce&task=plugin&plugin=imgmanager&file=imgmanager&method=form&cid=20&6bc427c8a7981f4fe1f5ac65c1246b5f=cf6dd3cf1923c950586d0dd595c8e20b HTTP/1.1" 499 0 "-" "BOT/0.1 (BOT for JCE)" 121.97.137.10 - - [09/Jul/2014:03:23:03 +0530] "POST /index.php?option=com_jce&task=plugin&plugin=imgmanager&file=imgmanager&method=form&cid=20&6bc427c8a7981f4fe1f5ac65c1246b5f=cf6dd3cf1923c950586d0dd595c8e20b HTTP/1.1" 499 0 "-" "BOT/0.1 (BOT for JCE)" This server does NOT run Joomla My understanding is that a BOT was randomly scanning the web for Joomla installations with the JCE exploit. It POSTed some file content and closed the request (Nginx status 499 - Client closed request). This POSTed content ended up with a tmp_name in the /tmp directory as the request did not complete. Is this correct? What else should I check to see if this was just a failed attempt or something more than that? Let me know if more information is required.
By default, something like gpg -d file.gpg sends it's output to stdout. What happens to input that is sent to stdout? Is it possible to recover this?
I am very familiar with OpenPGP but don't even use X.509 / S/MIME. I know that there are several classes for certificates (from email check to personal ID check). I would like to know how you determine the class of a certificate. Is this information part of the CA signature? Or is that an organuzational feature only, using different root certificates for different classes? I noticed that one CA has different root certificates which have the class number in their name. Is there a real attribute for a root certificate which tells the user the class?
For this question, I'm calling an "invisible CA" one that Is signed by a root ca and exists as a 2nd or 3rd tier Is valid, not expired or revoked Has a different Public key than one that is currently dominant and active This scenario could occur in reality when A normal subCA (root0-1) gets renewed* A malicious or virus infected rootCA operator signs an additional CA (root0-2) on the side The operator then signs/renews the legitimate & expected root CA (root0-1 becomes root0-3). My goal is to gain insight into a given PKI hierarchy as a consumer, or someone who trusts an issued certificate, and not rely on top down 3rd party audits and HSM with key counting. I would much rather have a cryptographic promise that will tell me how many times a sub-CA has been issued, and if those issued CAs are active/non revoked. A similar but different concept is the path length; I'm focused on quantity of active CAs for a given path value. Limited Show Credentials I have heard of cryptographic techniques that limit the number of times a key can be used (such as ECash) and that would expose a "secret". In this case perhaps the "secret" would be a boolean "complies with stated agreements" or "does not comply with stated agreements". But there are flaws with this approach, such as the client needs to monitor any and all subCAs that are transmitted to even detect such an event. Question Is there a more sensible approach (in theory) for clients to verify this aspect of integrity of PKI? (or any trust network of "authorities")
If I wanted to crack a password, "cba", but the dictionary I was using only had abc in it, does a dictionary attack try all combinations of abc? abc, acb, bca, bac, cba, cab Or would cba have to be specified in the dictionary in order to try it?
Recently an employee of mine developed a website in WordPress. Things were all fine until we received an email from Google , notifying me that some stuff that can really create security issues is going on in the WordPress site. On checking the FTP, I found an unusual folder there!! I could not delete it or modify it. The permission of the file was with the folder owner,changing which,most weirdly, I did not have permission! So I update WordPress thinking that it would solve the issue. Again, it was fixed for Sometime, but now I am receiving 1000 and more emails from an unknown account. The mail server of the site is over flooded and the client is on fire! I suspect this to be a DOS attack (Denial of service). How can I solve this? Any suggestion would make me indebted. Thank you in advance!!
Lets say there is an AJAX application where the user can submit items - buy them. And there was a code IF ($_POST[items] > 20) { echo 'error'; } else { do_buy($_POST[items]); echo 'success' } Here, there is a check if items is not more than 20. On client side, it should not be possible to choose more than 20 items. The system would work without problems even if 21 (or more) items were submitted (the user would simply pay for each item). While I realize you must want to yell don't trust the client, is there any harm in doing so if there are no consequences, as is the case here? One could make the argument that overloading the cart might cause instability in the system but it seems as though the worst case would be that some script times out. If errors are disable, the user will just not get back any response. In general: Does it make sense to code protections for an attack which violates an invariant of your system? Update: $_POST['items'] I meant that is array, not an integer. And each item how own properties - id and quantity, which are checked later before completing the buy operation. About sql injection - I usually use frameworks, and they take care of injection protection. Update One more reason why I ask this is I want as much clean code as possible and also when someone reads it - will think why the hell this is needed, this programmer does not know what he is programming and why. So for all code I want to have clear reason why that piece of code exists and so if not in comment, then at least myself that I would have clear understanding why I make this check so I could explain if another programmer asks.
With the recent announcement of Touch ID APIs for third party apps, I am wondering how can we leverage this feature to perform secure transaction ? I am looking for a method to use Touch ID in my payment application. One option is to store the password in the keychain and add access policies to invoke Touch ID during payment but the problem is if the device password is compromised, user can roll back to device password to access password stored in keychain. Does anyone know a better mechanism to manage password & make the transaction smoother & secure using Touch ID ?
While reading about NOTRACK target of raw table in iptables, I encountered an article suggesting that for certain traffic you could (or even should) disable connection tracking. The two examples were: (1) all kind of routed packets, and (2) if you have a web server, or other services that eat resources, you should also disable connection tracking for such service. I don't have a web server, but I do have some p2p clients. The following are standard rules for connection tracking: iptables -t filter -A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT iptables -t filter -A INPUT -m conntrack --ctstate INVALID -j DROP iptables -t filter -A INPUT -p udp -m conntrack --ctstate NEW -j udp iptables -t filter -A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -m conntrack --ctstate NEW -j tcp and in the udp and tcp chains I open port for a torrent client using: iptables -t filter -A udp -p udp --dport 33333 -m conntrack --ctstate NEW -j ACCEPT iptables -t filter -A tcp -p tcp --dport 33333 -m conntrack --ctstate NEW -j ACCEPT When I check conntrack entries: # cat /proc/net/nf_conntrack | wc -l 3569 Now the option would be to set NOTRACK in raw table for this kind of traffic, for instance: iptables -t raw -A notrack_in -p udp --dport 33333 -j NOTRACK iptables -t raw -A notrack_in -p udp --dport 33333 -j ACCEPT iptables -t raw -A notrack_in -p tcp --dport 33333 -j NOTRACK iptables -t raw -A notrack_in -p tcp --dport 33333 -j ACCEPT and it needs also two rules in the filter table: iptables -t filter -A INPUT -p udp --dport 33333 -j ACCEPT iptables -t filter -A INPUT -p tcp --dport 33333 -j ACCEPT After this operation, the number of entries in /proc/net/nf_conntrack dropped to 150-200, and there's no line with port 33333. My question is this: Is it safe to disable connection tracking? Would doing so necessitate adding rules to iptables? What are the pros and cons of this solution?
I wish to start with blackberry mobile application penetration testing. I researched on net but no "in-depth" knowledge is available. Here is a good article but not much is covered. http://resources.infosecinstitute.com/security-assessment-of-blackberry-applications/ I had a look at this question BlackBerry handheld penetration testing The above question targets the handhelds and not a particular mobile app. It would be great to get any help regarding how to pentest blackberry mobile "app". Any help is highly appreciated.
Is there any reversible hash function? The hash function like SHA and MD5 are not reversible. I would like to know if there exist some reversible hash functions?
I am looking forward to learn more on implementing SSL/TLS, can anyone of you suggest me a good source to learn about it? For now I only have basic knowledge about it such as what is SSL and how it works. Thanks.
I yesterday visited a restaurant I usually visit, but it seems that after paying with my debit card, I accidentally left it there. Today (almost 24 hours later) I had realized that I didn't have it with me anymore. I am not really that concerned about the unauthorized use of the card, since my previous experience with this bank (Bank of America) resulted in them cancelling any unauthorized payment first and asking questions later. However, I'm concerned about what I don't know: what are the risks of leaving it unattended for a while? This question pointed on the fact that asking for the zip code plays the extra role of verifying the actual owner -- but this restaurant never required me to indicate my zip code in order to pay them. Risks that come to mind but I'd like someone to help solidify by explaining on how this may contribute are: identity theft unauthorized payments (card theft) hacking other services that check on the last 4 digits of the card anything else I may have missed? Sidenote: I rarely contribute but read on this StackExchange site and find it awesomely helpful. If anyone has suggestions on how to make this question helpful to others (maybe making it broader?), please go ahead and provide your ideas.
In my application, I build REST APIs so that user can interact with my application server. Since I do not want to maintain User/Passwords, my iOS app authenticates client using Google. This all happens on iOS device Once client is authenticated, I would give a call to my app server to fetch user's data. The problem lies here. Now the user is authenticated on mobile client, but on server, I have no idea if the request is coming from a valid user or not. Question What are some mechanisms recommended to build trust between mobile client(authenticated with OAuth) and my server APIs
Google, Facebook, Twitter, and several other services still knows the older passwords which we used on our accounts. At times, I can not reuse the same password as I have. Then with Google, if I type an old password by mistake, it tells me when I last changed my password. I think this could be more or less of a security threat over doing any good. Why would these companies want to keep old passwords and information such as that? How much do we need to worry about them keeping that information, if someone was to break into our accounts?
From what I have noticed, there is very few services that offer the Remember Email over Remember Me or Sign-in Automatically. These options really do make the life easier for the end-user of applications. I strongly think that Remember Email would be way better with making the user input their password into the password field. Also, it would boost security with doing it that method (e.g. CreditKarma as an example). Would it be more secure if we do Remember Email and make our users put in their passwords each time they have to login to systems?
I ordered a Nokia phone online and it turned out that the packet had been tampered and the phone was missing from the package. Obviously it does not have a SIM card, etc. I assume someone stole it and is using the phone with a new SIM card. Is there any way that the phone can be tracked ?