CVE-2023-47124: Denial of service whith ACME HTTPChallenge in Traefik
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.
Other sources
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.
Affected Software
Event History
Frequently Asked Questions
What is the impact of CVE-2023-47124?
The vulnerability allows for a denial of service attack when Traefik is configured to use the ACME HTTP challenge.
How does CVE-2023-47124 affect Traefik?
The vulnerability affects Traefik versions 2.10.6 and earlier, as well as 3.0.0-beta5 and earlier.
What is the severity level of CVE-2023-47124?
The severity level of CVE-2023-47124 is medium with a CVSS score of 5.9.
How can I fix CVE-2023-47124?
To fix the vulnerability, update Traefik to version 2.10.6 or later for Traefik v2, or version 3.0.0-beta5 or later for Traefik v3.
Where can I find more information about CVE-2023-47124?
You can find more information about CVE-2023-47124 at the following references: [link1], [link2], [link3].