5.4
Medium
puma

CVE-2024-45614

CVE-2024-45614 is a medium-severity security vulnerability in puma (rubygems), affecting versions < 5.6.9. It is fixed in 5.6.9, 6.4.3.

Key facts
CVSS score
5.4
Medium
Attack vector
Network
Issuing authority
GitHub Advisory Database
Affected package
puma
Fixed in
5.6.9, 6.4.3
Disclosed
2024

Summary

Impact Clients could clobber values set by intermediate proxies (such as X-Forwarded-For) by providing a underscore version of the same header (X-ForwardedFor). Any users trusting headers set by their proxy may be affected. Attackers may be able to downgrade connections to HTTP (non-SSL) or redirect responses, which could cause confidentiality leaks if combined with a separate MITM attack. Patches 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. Workarounds Nginx has a underscoresinheaders configuration variable to discard these headers at the proxy level. Any users that are implicitly trusting the proxy defined headers for security or availability should immediately cease doing so until upgraded to the fixed versions.

Impact

Severity and exposure

CVE-2024-45614 has a CVSS score of 5.4 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.

A fixed version is available (5.6.9, 6.4.3). Upgrading removes the vulnerable code path.

Affected versions

rubygems

  • puma (< 5.6.9)
  • puma (>= 6.0.0, < 6.4.3)

Security releases

  • puma → 5.6.9 (rubygems)
  • puma → 6.4.3 (rubygems)
Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.

Kodem's runtime-powered SCA identifies whether CVE-2024-45614 is reachable in your applications. Explore open-source security for your team.

See if CVE-2024-45614 is reachable in your applications. Get a demo

Remediation advice

Upgrade the following packages to resolve this vulnerability:

  • Upgrade puma to 5.6.9 or later
  • Upgrade puma to 6.4.3 or later

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently asked questions about CVE-2024-45614

What is CVE-2024-45614?

CVE-2024-45614 is a medium-severity security vulnerability in puma (rubygems), affecting versions < 5.6.9. It is fixed in 5.6.9, 6.4.3.

How severe is CVE-2024-45614?

CVE-2024-45614 has a CVSS score of 5.4 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which versions of puma are affected by CVE-2024-45614?

puma (rubygems) versions < 5.6.9 is affected.

Is there a fix for CVE-2024-45614?

Yes. CVE-2024-45614 is fixed in 5.6.9, 6.4.3. Upgrade to this version or later.

Is CVE-2024-45614 exploitable, and should I be worried?

Whether CVE-2024-45614 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo

What actually determines whether CVE-2024-45614 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2024-45614?
  • Upgrade puma to 5.6.9 or later
  • Upgrade puma to 6.4.3 or later

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