Input validation error in Ruby on Rails - CVE-2011-3187
Published: September 29, 2025
Vulnerability identifier: #VU116156
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Green
CVE-ID: CVE-2011-3187
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
Public exploit is available
Vendor: Rails
Affected software:
Ruby on Rails
Ruby on Rails
Detailed vulnerability description
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to to_s method in actionpack/lib/action_dispatch/middleware/remote_ip.rb in Ruby on Rails does not validate the X-Forwarded-For header in requests from IP addresses on a Class C network. A remote attacker can pass specially crafted input to the application and gain access to potentially sensitive information.
How to mitigate CVE-2011-3187
Install updates from vendor's website.
Sources
- http://archives.neohapsis.com/archives/fulldisclosure/2011-02/0337.html
- http://webservsec.blogspot.com/2011/02/ruby-on-rails-vulnerability.html
- 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.novell.com/show_bug.cgi?id=673010