Improper Handling of URL Encoding (Hex Encoding) Affecting github.com/traefik/traefik/v3/pkg/server package, versions <3.0.0-beta5


Severity

Recommended
0.0
medium
0
10

CVSS assessment made by Snyk's Security Team

    Threat Intelligence

    Exploit Maturity
    Proof of concept
    EPSS
    0.06% (27th percentile)

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  • Snyk ID SNYK-GOLANG-GITHUBCOMTRAEFIKTRAEFIKV3PKGSERVER-6100475
  • published 7 Dec 2023
  • disclosed 4 Dec 2023
  • credit Khang Tran

How to fix?

Upgrade github.com/traefik/traefik/v3/pkg/server to version 3.0.0-beta5 or higher.

Overview

Affected versions of this package are vulnerable to Improper Handling of URL Encoding (Hex Encoding) when a request is sent with a URL fragment. An attacker can bypass frontend proxy URI-based access control restrictions by exploiting the automatic URL encoding and forwarding of the fragment to the backend server.

Note:

This is only exploitable if another frontend proxy like Nginx is used.

CVSS Scores

version 3.1
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Snyk

Recommended
4.8 medium
  • Attack Vector (AV)
    Network
  • Attack Complexity (AC)
    High
  • Privileges Required (PR)
    None
  • User Interaction (UI)
    None
  • Scope (S)
    Unchanged
  • Confidentiality (C)
    Low
  • Integrity (I)
    Low
  • Availability (A)
    None
Expand this section

NVD

6.5 medium