SB2021080346 - Inconsistent interpretation of HTTP requests in Traefik
Published: August 3, 2021 Updated: May 5, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Inconsistent interpretation of HTTP requests (CVE-ID: CVE-2021-32813)
The vulnerability allows a remote attacker to remove security-relevant request headers.
The vulnerability exists due to improper handling of hop-by-hop headers in Connection header processing when handling crafted HTTP requests through a chain of middlewares. A remote attacker can send a specially crafted request with a malicious Connection header to remove security-relevant request headers.
This can occur when one middleware sets a request header that is later stripped before the request is forwarded to the backend.
Remediation
Install update from vendor's website.