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Fencer Vulns
medium 4.8

CVE-2023-47106 json

Incorrect processing of fragment in the URL leads to Authorization Bypass in Traefik

published 2023-12-04 2 y ago modified 2026-08-07 3 mo ago also GHSA-fvhj-4qfh-q2hm , GO-2023-2376 , EUVD-2023-3201

cvss
4.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits
0
none known

Summary

Traefik is an open source HTTP reverse proxy and load balancer. When a request is sent to Traefik with a URL fragment, Traefik automatically URL encodes and forwards the fragment to the backend server. This violates RFC 7230 because in the origin-form the URL should only contain the absolute path and the query. When this is combined with another frontend proxy like Nginx, it can be used to bypass frontend proxy URI-based access control restrictions. This vulnerability has been addressed in versions 2.10.6 and 3.0.0-beta5. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Patch / fix

  • go github.com/traefik/traefik/v2 2.10.6
  • go github.com/traefik/traefik/v3 3.0.0-beta5
  • traefik2 openSUSE Tumbleweed 2.11.5-1.1
  • traefik openSUSE Tumbleweed 2.10.7-1.1

opensuse advisories openSUSE-SU-2024:14076-1openSUSE-SU-2024:13506-1

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/traefik/traefik/security/advisories/GHSA-fvhj-4qfh-q2hm referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 4.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
go github.com/traefik/traefik/v2
<2.10.6
2.10.6
go github.com/traefik/traefik/v3
<3.0.0-beta5
3.0.0-beta5
go github.com/traefik/traefik
all versions
 no fix listed

Affected products

  • traefik traefik

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-177 Improper Handling of URL Encoding (Hex Encoding)

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.