CVE-2021-32813 Drop Headers via Malicious Connection Header

2021-08-0322:50:11

CWE-913

GitHub_M

www.cve.org

4.8 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

LOW

Integrity Impact

LOW

Availability Impact

NONE

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

0.002 Low

EPSS

Percentile

64.8%

JSON

Traefik is an HTTP reverse proxy and load balancer. Prior to version 2.4.13, there exists a potential header vulnerability in Traefik’s handling of the Connection header. Active exploitation of this issue is unlikely, as it requires that a removed header would lead to a privilege escalation, however, the Traefik team has addressed this issue to prevent any potential abuse. If one has a chain of Traefik middlewares, and one of them sets a request header, then sending a request with a certain Connection header will cause it to be removed before the request is sent. In this case, the backend does not see the request header. A patch is available in version 2.4.13. There are no known workarounds aside from upgrading.

CNA Affected

[
  {
    "product": "traefik",
    "vendor": "traefik",
    "versions": [
      {
        "status": "affected",
        "version": "< 2.4.13"
      },
      {
        "status": "affected",
        "version": "<= 1.7.30"
      }
    ]
  }
]