Traefik: lowercase `Connection` tokens can delete traefik-managed forwarded identity headers (for example, `X-Real-Ip`)
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 2.11.38, 3.6.9
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
Traefik is an HTTP reverse proxy and load balancer. From version 2.11.9 to 2.11.37 and from version 3.1.3 to 3.6.8, there is a potential vulnerability in Traefik managing the Connection header with X-Forwarded headers. When Traefik processes HTTP/1.1 requests, the protection put in place to prevent the removal of Traefik-managed X-Forwarded headers (such as X-Real-Ip, X-Forwarded-Host, X-Forwarded-Port, etc.) via the Connection header does not handle case sensitivity correctly. The Connection tokens are compared case-sensitively against the protected header names, but the actual header deletion operates case-insensitively. As a result, a remote unauthenticated client can use lowercase Connection tokens (e.g. Connection: x-real-ip) to bypass the protection and trigger the removal of Traefik-managed forwarded identity headers. This issue has been patched in versions 2.11.38 and 3.6.9.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- traefik traefik
From 2.11.9 · fixed in 2.11.38; From 3.1.3 · fixed in 3.6.9
- github.com/traefik/traefik/v2Go
From 2.11.9 · fixed in 2.11.38
- github.com/traefik/traefik/v3Go
From 3.1.3 · fixed in 3.6.9
- github.com/traefik/traefikGo
All versions