CVE-2023-47124
mediumpriority · track · 24EPSS 0.008 · 56 %ileEUUSEPSS · scored 2026-10-27
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
weaknesses
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affected products (7)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- GHSA-8g85-whqh-cr2fTraefik vulnerable to potential DDoS via ACME HTTPChallenge2023-12-05ghsa · osvUS
## Impact There is a potential vulnerability in Traefik managing the ACME HTTP challenge. When Traefik is configured to use the [HTTPChallenge](https://doc.traefik.io/traefik/https/acme/#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](https://www.cloudflare.com/learning/ddos/ddos-attack-tools/slowloris/)). ## 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](https://doc.traefik.io/traefik/https/acme/#tlschallenge) or the [DNSChallenge](https://doc.traefik.io/traefik/https/acme/#dnschallenge). ## For more information If you have any questions or comments about this advisory, please [open an issue](https://github.com/traefik/traefik/issues).
- GO-2023-2381Traefik vulnerable to potential DDoS via ACME HTTPChallenge in github.com/traefik/traefik2024-08-21vendor · osvUS
Traefik vulnerable to potential DDoS via ACME HTTPChallenge in github.com/traefik/traefik
also known as (5)
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sources
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references (18)
External citations — patches, advisories, analysis.
- https://doc.traefik.io/traefik/cnnvd
- https://github.com/traefik/traefik/releases/tag/v2.10.6cnnvd
- https://github.com/traefik/traefik/releases/tag/v3.0.0-beta5cnnvd
- https://github.com/traefik/traefik/security/advisories/GHSA-8g85-whqh-cr2fcnnvd
- https://doc.traefik.io/traefik/https/acme/#dnschallengeenisa_euvd
- https://doc.traefik.io/traefik/https/acme/#httpchallengeenisa_euvd
- https://doc.traefik.io/traefik/https/acme/#tlschallengeenisa_euvd
- https://github.com/traefik/traefik/releases/tag/v2.10.6enisa_euvd
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