Denial of service whith ACME HTTPChallenge in Traefik
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.9epss 0.8%
exploitation probability
0.8%top 47% of all CVEs
observed exploitation
nono source reports it
Traefik is an open source HTTP reverse proxy and load balancer. 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 to achieve a `slowloris attack`. This vulnerability has been patch in version 2.10.6 and 3.0.0-beta5. Users are advised to upgrade. Users unable to upgrade should replace the `HTTPChallenge` with the `TLSChallenge` or the `DNSChallenge`.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
traefik · traefikReferences
https://doc.traefik.io/traefik/https/acme/#dnschallengehttps://doc.traefik.io/traefik/https/acme/#httpchallengehttps://doc.traefik.io/traefik/https/acme/#tlschallengehttps://github.com/traefik/traefik/releases/tag/v2.10.6https://github.com/traefik/traefik/releases/tag/v3.0.0-beta5https://github.com/traefik/traefik/security/advisories/GHSA-8g85-whqh-cr2fhttps://www.cloudflare.com/learning/ddos/ddos-attack-tools/slowloristtps://www.cloudflare.com/learning/ddos/ddos-attack-tools/slowloris/