CVE-2023-47124 — Traefik is an open source HTTP reverse proxy and load balancer

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

01What is this vulnerability?

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…

02Affected products

Vendor	Product	Versions
traefik	traefik	< 2.10.6, >= 3.0.0-beta1, < 3.0.0-beta5

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-12-04T20:20:30.727Z
• Last modified: 2024-12-18T14:12:58.629Z

09References

• github.com — https://github.com/traefik/traefik/security/advisories/GHSA-8g85-whqh-cr2f
• doc.traefik.io — https://doc.traefik.io/traefik/https/acme/#dnschallenge
• doc.traefik.io — https://doc.traefik.io/traefik/https/acme/#httpchallenge
• doc.traefik.io — https://doc.traefik.io/traefik/https/acme/#tlschallenge
• github.com — https://github.com/traefik/traefik/releases/tag/v2.10.6
• github.com — https://github.com/traefik/traefik/releases/tag/v3.0.0-beta5
• www.cloudflare.com — https://www.cloudflare.com/learning/ddos/ddos-attack-tools/slowloris