CVE-2023-47124
Denial of service whith ACME HTTPChallenge in Traefik
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Denial of service whith ACME HTTPChallenge in Traefik
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.
- Record
CVE-2023-47124- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-772
- Updated
- 2026-11-02
EUVDEUVD-2023-3160
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.
- Record
EUVD-2023-3160- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-8g85-whqh-cr2f
Traefik vulnerable to potential DDoS via ACME HTTPChallenge
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.
- Record
GHSA-8g85-whqh-cr2f- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400, CWE-772
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2023-47124- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-772
- Updated
- 2026-11-02
OSV
Denial of service whith ACME HTTPChallenge in Traefik
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.
- Record
CVE-2023-47124- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-772
- Updated
- 2026-11-02
OSVGHSA-8g85-whqh-cr2f
Traefik vulnerable to potential DDoS via ACME HTTPChallenge
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.
- Record
GHSA-8g85-whqh-cr2f- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400, CWE-772
- Updated
- 2026-11-02
OSVGO-2023-2381 No score
Traefik vulnerable to potential DDoS via ACME HTTPChallenge in github.com/traefik/traefik
Traefik vulnerable to potential DDoS via ACME HTTPChallenge in github.com/traefik/traefik
- Record
GO-2023-2381- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:13506-1 No score
traefik-2.10.7-1.1 on GA media
These are all security issues fixed in the traefik-2.10.7-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:13506-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:14076-1 No score
traefik2-2.11.5-1.1 on GA media
These are all security issues fixed in the traefik2-2.11.5-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:14076-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/traefik/traefik/v2Go |
before 2.10.6 | 2.10.6 |
github.com/traefik/traefik/v3Go |
before 3.0.0-beta5 | 3.0.0-beta5 |
github.com/traefik/traefikGo |
All versions | None known |
traefikopenSUSE:Tumbleweed From an advisory covering 6 CVEs |
before 2.10.7-1.1 | 2.10.7-1.1 |
traefik2openSUSE:Tumbleweed From an advisory covering 15 CVEs |
before 2.11.5-1.1 | 2.11.5-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-47124 is a medium vulnerability (CVSS 5.9) in Traefik, published December 4, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.79%, the 56th percentile. Fixed in github.com/traefik/traefik/v2 2.10.6.
References
github.com/traefik/traefik/security/advisories/GHSA-8g85-whqh-cr2f
doc.traefik.io/traefik/https/acme
cloudflare.com/learning/ddos/ddos-attack-tools/slowloris
nvd.nist.gov/vuln/detail/CVE-2023-47124
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suse.com/security/cve/CVE-2023-39325