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Jan
31
comment chrome red lock icon this page includes other resources which are not secure these resources can be viewd by others while in transit
@dave_thompson_085 - Yes. Sorry my answer was condensed and a tad unclear from being forced to be comments. Being vulnerable to POODLE TLS is a flaw in the webserver (patchable); supporting PFS and using good protocols (not SSLv3) and ciphers is a server config issue (might require webserver upgrade). By the way, NIST deprecated SHA1 for digital signatures in Jan 2011 and disallowed after 2013 (pdf). However, it was still often used as some outdated browsers (e.g., IE6-8 on XP before SP3) didn't support SHA-2 signatures.
Jan
30
comment chrome red lock icon this page includes other resources which are not secure these resources can be viewd by others while in transit
The problem with SHA-1 signatures is that with the advent of data centers and increase in computing power (along with work finding flaws in SHA-1 design), very sophisticated attackers with access to lots of computing power in principle can with much effort create SHA-1 collisions (or should be able to in the near future) which would allow them to do man-in-the-middle attacks (and steal your information). Forward secrecy is a good property to have, but not having it doesn't mean your connection can be eavesdropped or tampered with.
Jan
30
comment chrome red lock icon this page includes other resources which are not secure these resources can be viewd by others while in transit
uk.cricut.com needs to update their certificates as their current deployment has several attackable vulnerabilities (POODLE, POODLE TLS, maybe FREAK, doesn't support forward secrecy). They need to upgrade and patch their webserver to support TLS 1.2 and prevent POODLE TLS, stop using SHA-1 signatures, support forward secrecy, and stop supporting obsolete outdated ciphers. Granted, most likely the web site is still safe. POODLE attacks require attackers to insert malicious javascript into clients.
Jan
29
comment Is random URL token secure enough for file attachments and other user content?
@SteveDL And sure my email provider or gov't can probably read my emails getting these secret links. But still example.com where I've uploaded the file can see my file and provide them to the gov't when requested even if I maintain strict access control. And for things like say family pictures, the token in the URL makes it much easier to email the pics to some family members and let those family members share the link to the album to people you may have forgotten (without having to request access) or having the family member download the images to share them with the person you forgot.
Jan
29
comment Is random URL token secure enough for file attachments and other user content?
@SteveDL This question was random tokens in a URL for file attachments to private messages. If I want to send friends a link to a 100MB video file/photo album that I'd otherwise include as an email attachment, but instead provide an access link at https://example.com/private/<random token> (with a robots.txt telling search engines to never index /private/ and the random token appears after that) this is as secure as an attachment. Yes, a malicious friend could share the link with other people who I haven't given access, but with any scheme they can download the file and upload it elsewhere.
Jan
29
comment Is random URL token secure enough for file attachments and other user content?
@SteveDL Your duplicate question asked a different question. That question was about having all content served from one obscurely named directory that then hosts all the content. The reason that doesn't work is the same reason all paying subscribers to the Wall St Journal shouldn't just be given the same password for simplicity. The password would leak. See the answers to this very similar question ( security.stackexchange.com/questions/36870/… ), where the answers agree it is not security by obscurity.
Jan
28
comment Is random URL token secure enough for file attachments and other user content?
Use of random tokens is not security by obscurity. Security by obscurity is when security is lost if the implementation details (e.g., source code, algorithm) become available to the attacker. This contrasts with security by design where the implementation can be publicly known and only secret keys (passwords, random tokens, private keys) have to be kept secret. In this case the secret key is the randomly generated token. Of course, this fails if the secrets are leaked.
Jan
21
comment Is reading from prod to dev a security concern?
Is the copied data secret or confidential in any way? If so, copying it out of a locked down environment to a looser dev environment does create the opportunity for that information to leak out (due to any temporary flaws in the dev environment).
Jan
13
comment Is it possible for my password to have more than one password combination?
@A.L - I'm going to keep using tilde for approximately. It's a common succinct notation ( en.wikipedia.org/wiki/Tilde#Common_use ) for "approximately" (as a unary operator; e.g., about ~7 billion humans) or "approximately equal" (as a binary operator e.g., 2^10 ~ 10^3) and my answers already tend to be on the long side. I'd rather just explain this notation to people unfamiliar with it if they ask.
Jan
13
comment Is it possible for my password to have more than one password combination?
@aross - It had two bad features; (1) password in plaintext/reversible encryption (forgot password features should require you to validate yourself and then set a new password), and (2) stripping out special characters from your password drastically weakens it. Take OP's pw !78ghA,NJ58*#3&* - 16 chars randomly chosen from 96 printable ASCII chars : ~105.4 bits of entropy (52040292466647269602037015248896 pws) - very secure. Stripping special chars makes it 59.5 bits (839299365868340224 pws) - much less secure. If numbers were also stripped its 28.5 bits (380,204,032 pws) - very weak.
Jan
13
comment Is it possible for my password to have more than one password combination?
In this context, it means approximately equals; it has other meanings in other math contexts, see en.wikipedia.org/wiki/Tilde#Mathematics . The main reason for not using the slightly clearer ≃ is that unicode is harder to type. As for where it comes from 2^256 = 115792089237316195423570985008687907853269984665640564039457584007913129639936 = 1.1579... x 10^77 ~ 10^77 (I originally had off-by-one typo). If you want to find what power it is you could just set 2^256 = 10^x then take the log of both sides and use well-known properties of logs to find x = 256 log(2) / log(10) ~ 77.
Jan
8
comment Does holding an AES-encrypted string and its cleartext from a database help an attacker in decrypting other parts of the database
Not saying anything is wrong with Xander's answer, but feel like adding that this answer assuming AES (the block cipher encryption function) is being used properly then it will be CPA-secure (as far as we know). If you used AES in say ECB mode (which should never be used), then an attacker can do chosen plaintext attacks on your database by encrypting various likely plaintexts and seeing wherever it matches encrypted data. Or if you used AES in CTR mode but the same seed is used to encrypt different data, then you've lost semantic security if the attacker can do chosen-plaintext attacks.
Jan
2
comment GET Security over HTTPS
As well as Is there a difference between GET and POST for web application security? and probably several other questions.
Jan
2
comment Are zip codes considered to be personal identifying information?
@JanDoggen Really it depends on the legal authority and the specific use. It's probably safest to assume for personal use that it is PII and to appropriately deidentify as HHS suggests, but in most cases the five-digit zip alone will not be able to uniquely identify individuals.
Jan
2
comment Are zip codes considered to be personal identifying information?
I didn't directly answer it, because like many questions its not a simple yes/no. If your health care provider mails you a letter and your zip code is showing on the outside of an envelope to your mail carrier, is that a privacy breach? Obviously it would be if they printed your SSN, date of birth, credit card number on the envelope it would be. Or if only one family resides in a zip code and you are listed as a customer your privacy was violated (though this rare case happens for about 0.00001% of Americans), so it would break HIPAA to publicly state someone from 30334 had illness X.
Jan
1
comment Avoid unauthorized updating of online leaderboard php/sql
If a player submits a series of moves to your server that would produce a high score, your server checks that those moves give the player an appropriate high score even when the game was entirely played offline. Granted this doesn't validate that a human actually found those moves to play on an actual device (versus wrote an AI program to play the game well), but you'll never be able to verify it was done by humans without actually having trustworthy judges watch the human play the game. (And you can add in randomization by treating the seed to your RNG as part of the solution).
Jan
1
comment Avoid unauthorized updating of online leaderboard php/sql
In regards to (1), plenty of games played offline require you to download new levels prior to play. Offline in this context means no internet required while playing. In regards to (2) no, it doesn't require scores to be accepted from unmodified devices. It just requires your trusted server receiving submitted solutions to check the score produced by those moves. For example, say you wrote a Pacman clone that had no randomization (ghost actions only depend on your movements) and a discrete timer of moves (e.g., moves are only registered every tenth of second of the video game clock).
Jan
1
comment Avoid unauthorized updating of online leaderboard php/sql
Second, I agree this won't work for a mobile game with completely open source code that you can run on untrusted hardware. But I think it's worthwhile to say that while difficult this problem can be solved on trusted hardware that only runs trusted unmodified software (and this is how online high scores work for video games running on xbox, playstation, etc). And nothing in the question prevents this -- someone could design hardware devices that run a modified android that only runs signed javascript applications and digitally signs submitted scores.
Jan
1
comment Avoid unauthorized updating of online leaderboard php/sql
@TTT - First, about server time vs client time, reread what I wrote -- we are in agreement. I never said anything about trusting a client submitted time. I said you only trust the time that it was submitted as given by the server's clock and then validated server-side to work to produce a given score. I never said anything about looking at a client's time or the client submitting a time. E.g., a puzzle was released at noon and your leaderboard consists of the first people who submitted valid solutions with the times received by the server.
Dec
22
comment is g-zipping assets a security concern?
If the compression is done actively and includes compression of secrets (e.g., session cookies) there can be active attacks to steal those secrets, for example CRIME (where you guess parts of the secret and look for reduction in the compressed content when the guess is correct). That said in serving static resources (with no secret tokens included), there isn't a legitimate reason to not compress the static resource.