CVE-2011-3187

Severity: medium (CVSS 4.3 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 6.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2011-08-29 · updated 2026-06-16
Weakness: CWE-20

Description

The to_s method in actionpack/lib/action_dispatch/middleware/remote_ip.rb in Ruby on Rails 3.0.5 does not validate the X-Forwarded-For header in requests from IP addresses on a Class C network, which might allow remote attackers to inject arbitrary text into log files or bypass intended address parsing via a crafted header.

Affected products

Ruby on Rails: 3.0.5

References

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
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

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