Cross-site scripting - CVE-2011-2931

Detailed vulnerability description

Vulnerability allows a remote attacker to perform XSS attacks.

The vulnerability is caused by an input validation error in the strip_tags helper in actionpack/lib/action_controller/vendor/html-scanner/html/node.rb in Ruby on Rails before 2.3.13, 3.0.x before 3.0.10, and 3.1.x before 3.1.0.rc5. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in victim's browser in security context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

How to mitigate CVE-2011-2931

Sources

• http://groups.google.com/group/rubyonrails-security/msg/fd41ab62966e0fd1?dmode=source&output=gplain
• http://lists.fedoraproject.org/pipermail/package-announce/2011-September/065109.html
• http://lists.fedoraproject.org/pipermail/package-announce/2011-September/065137.html
• http://lists.fedoraproject.org/pipermail/package-announce/2011-September/065212.html
• http://secunia.com/advisories/45921
• http://weblog.rubyonrails.org/2011/8/16/ann-rails-3-1-0-rc6
• http://www.debian.org/security/2011/dsa-2301
• http://www.openwall.com/lists/oss-security/2011/08/17/1
• http://www.openwall.com/lists/oss-security/2011/08/19/11
• http://www.openwall.com/lists/oss-security/2011/08/20/1
• http://www.openwall.com/lists/oss-security/2011/08/22/13
• http://www.openwall.com/lists/oss-security/2011/08/22/14
• http://www.openwall.com/lists/oss-security/2011/08/22/5
• https://bugzilla.redhat.com/show_bug.cgi?id=731436
• https://github.com/rails/rails/commit/586a944ddd4d03e66dea1093306147594748037a