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12
votes
0answers
2k views

Should I Use Base64 or Unicode for Storing Hashes & Salts? [migrated]

I have never worked on the security side of web apps, as I am just out of college. Now, I am looking for a job and working on some websites on the side, to keep my skills sharp and gain new ones. One ...
1
vote
1answer
84 views

Minimum SHA256'd UTF8 encoded passphrase length not stored anywhere

For a passphrase that is UTF8 encoded and then SHA256'd, what is the minimum length to achieve a practically collision free result? The implementation is for a 32 byte cryptocurrency ed25519 seed ...
0
votes
4answers
895 views

SQL Injection via Unicode

My team currently uses ASP.NET with MS SQL Server for our software. Security has only become important since I started, in which there is injection vulnerabilities everywhere. Due to current ...
6
votes
2answers
885 views

PHP: if charset mismatches (htmlentities UTF-8) viewed by client as ISO-8859-1 (or vice versa)

Short Question: Question: Could any security vulnerabilities arise if a server runs htmlentities as UTF-8 but the client views the results as ISO-8859-1? Assumption: No vulnerabilities exist when ...
6
votes
1answer
162 views

Is it okay to normalize unicode passwords with NFC/NFD?

I am currently designing a login for a web service. I will use a PBKDF2 implementation for hashing the passwords. However, I intend to allow unicode for passwords, as I will have international users, ...
4
votes
1answer
1k views

Why does Directory traversal attack %C0%AF work?

Introduction: I am trying to learn the basics of Directory Traversal. Question: While trying to understand the 2-Byte Unicode conversion of characters, I came across this_SANS ARTICLE that explains ...
4
votes
2answers
399 views

Is there a dictionary of visibly similar Unicode characters for Spam processing?

I have spam that looks like this: мy вυddy'ѕ мoм мαĸeѕ $74/нoυr oɴ тнe lαpтop. ѕнe нαѕ вeeɴ lαιd oғғ ғor ѕeveɴ мoɴтнѕ вυт lαѕт мoɴтн нer pαy cнecĸ wαѕ $19420 jυѕт worĸιɴɢ oɴ тнe lαpтop ғor α ...
3
votes
1answer
762 views

XSS via Unicode

Reading about XSS and its countermeasures from http://www.xssed.com/xssinfo#Avoiding_XSS_vulnerabilities , it says (in the 2nd last paragraph of the link) that: […] support for Unicode character ...
7
votes
3answers
2k views

Is there a way to bypass Django's XSS escaping with “unicode”?

Django (the Python web framework) escapes output to prevent XSS (Cross Site Scripting) attacks. It replaces ', ", <, >, & with their HTML safe versions. However this presentation on slide ...
4
votes
2answers
1k views

What exploit types do I need to protect against in PHP?

I recently learned that apparently, it is common for people to attempt SQL injections using the HTTP referrer in PHP. What other inputs do I need to protect against? I am currently "cleaning up" ...
3
votes
2answers
233 views

How to defend against invalid UTF7/8 that hides a <script> tag?

I'm scanning HTML before it reaches a browser, and I've just heard about a type of exploit that uses invalid UTF7 or UTF8 sequences to embed an otherwise invisible script tag, which is used to execute ...
19
votes
4answers
6k views

How did Anonymous use UTF-16 ASCII to fool PHP escaping?

A few months ago, Anonymous took down a child pornography site using SQL-injection. I read in this article that Anonymous claimed that "the server was using hardened PHP with escaping," but they were ...
6
votes
1answer
425 views

White list or black list sanitation for international input?

There seem to be so many ways to create nefarious input that white-listing what input is good usually feels like the safer, simpler option. For instance, one can fairly easily craft a white list ...
5
votes
2answers
257 views

What applications are at risk from “Backwards Unicode Names” and what are the mitigations?

There is a vulnerability where some applications (such as explorer.exe) respond to Unicode characters that change the direction of the text (right-to-left vs left-to-right). This may be used to mask ...