Dear bugtraq, Below is a digest of vulnerabilities in multiple CAPTCHA systems. All vulnerabilities were reported by MustLive (websecurity.com.ua) during "The Month of Bugs in CAPTCHA" 1. Peter’s Custom Anti-Spam Image < 2.9 (Wordpress plugin) 1.1 "antiselect" value can be guessed with 10% probability. 1.2 Same check pairs may be used for multiple postings According to vendor both problems were addressed in Version 2.9.0 on August 11, 2007 Original article: http://websecurity.com.ua/1501/ Exploit for 1.2: http://websecurity.com.ua/uploads/2007/MoBiC/Peter's%20Custom%20Anti-Spam%20Image%20CAPTCHA%20bypass.html 2. mt-scode CAPTCHA (plugin for Movable type and Drupal) Same check pairs may be used for multiple postings Original article: http://websecurity.com.ua/1516/ Exploit: http://websecurity.com.ua/uploads/2007/MoBiC/mt-scode%20CAPTCHA%20bypass.html 3. PHP-Nuke <= 8.1 3.1 Same check pairs may be used for multiple postings/registrations Original article: http://websecurity.com.ua/1527/ Exploit: http://websecurity.com.ua/uploads/2007/MoBiC/PHP-Nuke%20CAPTCHA%20bypass.html (posting) http://websecurity.com.ua/uploads/2007/MoBiC/PHP-Nuke%20CAPTCHA%20bypass2.html (registration) 3.2 NULL string CAPTCH bypass: if NULL string is given, CAPTCHA is not validated. Original article: http://websecurity.com.ua/1528/ Exploit: http://websecurity.com.ua/uploads/2007/MoBiC/PHP-Nuke%20CAPTCHA%20bypass3.html 4. Peter’s Random Anti-Spam Image <= 0.2.4 (Wordpress plugin) CAPTCHA may be bypassed by pre-generating possible image-code pairs. Original article: http://websecurity.com.ua/1534/ Exploit: http://websecurity.com.ua/uploads/2007/MoBiC/Peter's%20Random%20Anti-Spam%20Image%20CAPTCHA%20bypass.html 5. Cryptographp <= 1.12 (Wordpress plugin) It's possible to reuse same security code during session Originale article: http://websecurity.com.ua/1551/ Exploit: http://websecurity.com.ua/uploads/2007/MoBiC/Cryptographp%20CAPTCHA%20bypass.html 6. PHP-Fusion / HBH-Fusion (version not reported) CAPTCHA bypass It's possible to reuse same security code during session Original article: http://websecurity.com.ua/1558/ (PHP-Fusion) http://websecurity.com.ua/1561/ (HBH-Fusion) Exploit: http://websecurity.com.ua/uploads/2007/MoBiC/PHP-Fusion%20CAPTCHA%20bypass.html (PHP-Fusion) http://websecurity.com.ua/uploads/2007/MoBiC/HBH-Fusion%20CAPTCHA%20bypass.txt (HBH-Fusion) 7. Nucleus <= 3.01 CAPTCHA bypass 7.1 CAPTCHA may be bypassed by pre-generating possible image-code pairs. 7.2 SQL injection vulnerability can be used to bypass CAPTCHA Original article: (7.1) http://websecurity.com.ua/1564/ (7.2) http://websecurity.com.ua/1565/ Exploit: (7.1) http://websecurity.com.ua/uploads/2007/MoBiC/Nucleus%20CAPTCHA%20bypass.html (7.2) http://websecurity.com.ua/uploads/2007/MoBiC/Nucleus%20CAPTCHA%20bypass2.html 8. Auto-Input Protection (AIP) <= 2.0 (for ASP.Net) Same check pairs may be used for multiple postings Original article: http://websecurity.com.ua/1568/ Exploit: http://websecurity.com.ua/uploads/2007/MoBiC/AIP%20CAPTCHA%20bypass.html Vendor's suggested workaround: http://davesexton.com/blog/blogs/blog/archive/2007/12/12/aip-1-0-0-bypassed.aspx 9. Math Comment Spam Protection <= 2.1 (Wordpress plugin) Same check pairs may be used for multiple postings Original article: http://websecurity.com.ua/1575/ Exploit: http://websecurity.com.ua/uploads/2007/MoBiC/Math%20Comment%20Spam%20Protection%20CAPTCHA%20bypass.html 10. Anti Spam Image <= 0.5 (Wordpress plugin) It's possible to reuse same security code during session Original article: http://websecurity.com.ua/1584/ Exploit: http://websecurity.com.ua/uploads/2007/MoBiC/Anti%20Spam%20Image%20CAPTCHA%20bypass.html 11. Captcha! <= 2.5d (Wordpress plugin) It's possible to bypass CAPTCHA by combining crossite request forgery vulnerability with NULL string for security code. Original article: http://websecurity.com.ua/1587/ Exploit: http://websecurity.com.ua/uploads/2007/MoBiC/Captcha!%20CSRF.html (crossite request forgery) http://websecurity.com.ua/uploads/2007/MoBiC/Captcha!%20CAPTCHA%20bypass.html (CAPTCHA bypass) 12. WP-ContactForm <= 2.0.7 (Wordpress plugin) Same security code may be used for multiple times Original article: http://websecurity.com.ua/1599/ Exploit: http://websecurity.com.ua/uploads/2007/MoBiC/WP-ContactForm%20CAPTCHA%20bypass.html 13. Drupal (reCaptcha) unique captcha_token parameter without recaptcha_response_field may be used to bypass CAPTCHA. Vulnerability is reported in reCaptcha plugin for Drupal, but according to reCaptcha developers, vulnerability is in Drupal code. Original article: http://websecurity.com.ua/1505/ Exploit: http://websecurity.com.ua/uploads/2007/MoBiC/reCaptcha.txt -- http://securityvulns.com/ /\_/\ { , . } |\ +--oQQo->{ ^ }<-----+ \ | ZARAZA U 3APA3A } You know my name - look up my number (The Beatles) +-------------o66o--+ / |/