Year: 2013

  • Hash Length Extension in HTMLPurifier

    HTMLPurifier is a PHP library that helps to protect against XSS by filtering bad HTML and only allowing harmless markup. Recently a new version of HTMLPurifier has been released that fixes a hash length extension issue that I reported some time ago. Hash length extension is a crypto attack against algorithms based on Merkle-Damgard construction […]

  • Radamsa Fuzzer Extension for Burp Suite

    Radamsa is a cool tool that combines a set of fuzzers which generate data based on input string. You can feed it a PDF file for example and Radamsa will produce a bunch of PDF-alike documents that are fuzzed in all imaginable forms. Just see this: $ echo "test123" | radamsa -n 10 ttestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestestest1 tes.–1 […]

  • DEFCON CTF 2013 Quals “grandprix” Writeup

    This time at DEFCON CTF quals there was a special task category, namely OMGACM or competitive programming. Here is a solution to OMGACM 3 task. We have a remote host that offers to play a race game: Connected to Escape character is '^]'. Use 'l' and 'r' to move. Don't crash. Press return to […]

  • CONFidence 2013: PHP Object Injection Revisited

  • PHDays 2013 CTF “Blade” Writeup

    We have a simple form with login and password. There is an SQL injection, but a WAF blocks any attempt to bypass it. First step to solve this task was to reveal the contents of the script by requesting index.phps: <?php include 'flag.php'; if (!isset($_POST['username']) || !isset($_POST['password'])) { print <<<FORM <form method=POST> <input type=text name=username></input> […]

  • Simple Machines Forum <= 2.0.3 Admin Password Reset

    Simple Machines Forum is a popular web community software written in PHP. Its password reset mechanism had some issues back in 2008. The vulnerability was caused by insecure random numbers generation and was patched right after the exploit was published. This time I found a more interesting vulnerability however at Positive Technologies we didn’t manage […]