Auth bypass in Puma
CVE-2024-45614
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.
Vulnerability class: IDOR (Insecure Direct Object Reference)
EPSS: 0.006 (47.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N.
Affected products
- Puma — versions >= 6.0.0, < 6.4.3, < 5.6.9
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Product, x_refsource_MISC)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2024-45614?
- CVE-2024-45614 is a medium-severity vulnerability in Puma, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 5.4/10. Published 2024-09-19.
- How severe is CVE-2024-45614?
- Medium severity. CVSS v3 base score is 5.4 out of 10.
- Is CVE-2024-45614 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.