Puma Fixes Underscore Header Vulnerability

CVE-2024-45614
5.4MEDIUM

Key Information

Vendor
Puma
Status
Puma
Vendor
CVE Published:
19 September 2024

Badges

👾 Exploit Exists🔴 Public PoC

Summary

Puma is a Ruby/Rack web server built for parallelism. In affected versions clients could clobber values set by intermediate proxies (such as X-Forwarded-For) by providing a underscore version of the same header (X-Forwarded_For). Any users relying on proxy set variables is affected. v6.4.3/v5.6.9 now discards any headers using underscores if the non-underscore version also exists. Effectively, allowing the proxy defined headers to always win. Users are advised to upgrade. Nginx has a underscores_in_headers configuration variable to discard these headers at the proxy level as a mitigation. Any users that are implicitly trusting the proxy defined headers for security should immediately cease doing so until upgraded to the fixed versions.

Affected Version(s)

puma < 6.0.0, 6.4.3

puma < 5.6.9

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVSS V3.1

Score:
5.4
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Changed

Timeline

  • 👾

    Exploit exists.

  • Vulnerability published.

  • Vulnerability Reserved.

Collectors

NVD DatabaseMitre Database1 Proof of Concept(s)
.