Vulnerability · Published Sep 19, 2024 · Assigned by GitHub_M
CVE-2024-45614Header normalization allows for client to clobber proxy set headers in Puma
Medium 5.4
In plain English
A medium-severity authorization bypass via user-controlled key in puma from puma. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 51% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official description
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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | puma | 5.6.5-3+deb12u1 | DEBIAN-CVE-2024-45614 |
| Debian:13 | puma | 6.4.3-1 | DEBIAN-CVE-2024-45614 |
| Debian:14 | puma | 6.4.3-1 | DEBIAN-CVE-2024-45614 |
| RubyGems | puma | 5.6.9 | GHSA-9hf4-67fc-4vf4 |
| RubyGems | puma | 6.4.3 | GHSA-9hf4-67fc-4vf4 |
| Ubuntu:24.04:LTS | puma | 6.4.2-4ubuntu4.3 | USN-7031-1 |
| Ubuntu:24.04:LTS | puma | 6.4.2-4ubuntu4.3 | UBUNTU-CVE-2024-45614 |
Affected products (as reported)
Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N