Skip to main content
VulnerabilityPublished Updated

CVE-2024-45614: Puma's header normalization allows for client to clobber proxy set headers

Affects pumaSource GCVE Database

0
Compare
Authoritative record:CVE-2024-45614· Medium 5.4

Not known to be exploited · CVSS 5.4 Medium : upgrade to 5.6.9 when convenient.

Data as of 31 Oct 2026, 01:25 UTC

CVSS 3.1 base score
5.4Medium
How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none
CVSS scores by source
CNA (GitHub_M)CVSS 3.15.4
Patch
Available – fixed in 5.6.9, 6.4.3
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 19 Sep 2024

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

What to do

Upgrade puma to 5.6.9; puma to 6.4.3.

Affected software

ProductAffectedFixed in
RubyGemspumaAffected
  • <5.6.9
Fixed in
  • 5.6.9
RubyGemspumaAffected
  • >=6.0.0 <6.4.3
Fixed in
  • 6.4.3

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade Puma to version 5.6.9 or later, or 6.4.3 or later, where the vulnerability is fixed by discarding underscore headers when the non-underscore version exists. As a workaround, configure proxies such as Nginx to reject headers containing underscores using the 'underscores_in_headers' setting. Users should immediately stop trusting proxy-set headers if they have not yet applied the patch.

Description

CVE-2024-45614 is a vulnerability in Puma's header normalization that allows clients to override headers set by intermediate proxies by using underscore variants of header names. This can affect users who trust proxy-set headers, potentially enabling attackers to downgrade connections to HTTP or redirect responses, risking confidentiality if combined with a MITM attack. Fixed versions 5.6.9 and 6.4.3 discard underscore headers when the non-underscore version exists. Users relying on proxy headers for security should upgrade immediately or configure proxies like Nginx to discard underscore headers.

References

Community reviews

Loading reviews…