CGA-w5f8-74cv-xhp5

Summary

Traefik vulnerable to potential DDoS via ACME HTTPChallenge

Description

Impact

There is a potential vulnerability in Traefik managing the ACME HTTP challenge.

When Traefik is configured to use the HTTPChallenge to generate and renew the Let's Encrypt TLS certificates, the delay authorized to solve the challenge (50 seconds) can be exploited by attackers (slowloris attack).

Patches

• https://github.com/traefik/traefik/releases/tag/v2.10.6
• https://github.com/traefik/traefik/releases/tag/v3.0.0-beta5

Workarounds

Replace the HTTPChallenge with the TLSChallenge or the DNSChallenge.

For more information

If you have any questions or comments about this advisory, please open an issue.