Skip to main content
← All vulnerabilities
CVE-2020-5247GHSA-84J7-475P-HP8VBIT-RUBY-2020-5247BIT-RUBY-MIN-2020-5247

HTTP Response Splitting in Puma

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 3.12.3, 4.3.2, 3.12.4, 4.3.3
None on Exploit-DB, Metasploit or GitHub

Summary

In Puma (RubyGem) before 4.3.2 and before 3.12.3, if an application using Puma allows untrusted input in a response header, an attacker can use newline characters (i.e. `CR`, `LF` or`/r`, `/n`) to end the header and inject malicious content, such as additional headers or an entirely new response body. This vulnerability is known as HTTP Response Splitting. While not an attack in itself, response splitting is a vector for several other attacks, such as cross-site scripting (XSS). This is related to CVE-2019-16254, which fixed this vulnerability for the WEBrick Ruby web server. This has been fixed in versions 4.3.2 and 3.12.3 by checking all headers for line endings and rejecting headers with those characters.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • puma Puma

    fixed in 3.12.3; From 4.0.0 · fixed in 4.3.2

  • pumaRubyGems

    fixed in 3.12.4

  • pumaRubyGems

    From 4.0.0 · fixed in 4.3.3

References 7

GitHub · puma/puma

owasp.org

ruby-lang.org

lists.fedoraproject.org

lists.debian.org