Cyber Resilience

CVE-2024-39321

Access Control in Traefik ≤ 2.11.6

Published
05 July 2024
Modified
25 November 2025
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS Score 0.0059 45th percentile
Risk Priority 58 floored blend · peak EPSS

Summary

CVE-2024-39321 is a high-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Traefik Traefik. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 45th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-3 (Access Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Traefik is an HTTP reverse proxy and load balancer. Versions prior to 2.11.6, 3.0.4, and 3.1.0-rc3 have a vulnerability that allows bypassing IP allow-lists via HTTP/3 early data requests in QUIC 0-RTT handshakes sent with spoofed IP addresses. Versions 2.11.6,…

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3.0.4, and 3.1.0-rc3 contain a patch for this issue. No known workarounds are available.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-65600Same product: Traefik Traefik
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CVE-2025-32431Same product: Traefik Traefik
CVE-2025-54386Same product: Traefik Traefik
CVE-2026-29054Same product: Traefik Traefik
CVE-2025-66490Same product: Traefik Traefik
CVE-2026-53622Same product: Traefik Traefik
CVE-2026-48020Same product: Traefik Traefik
CVE-2026-40912Same product: Traefik Traefik
CVE-2026-48491Same product: Traefik Traefik

Affected Assets

traefik
traefik
3.1.0 · ≤ 2.11.6 · 3.0.0 — 3.0.4

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Enforcing approved authorizations on every access request structurally stops a user-controlled key from reaching another user's data.

Requiring explicit access-control decisions on each request blocks unauthorized key-driven access.

Least-privilege restrictions limit the scope of data reachable even if a key check is bypassed.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 full match
prevents

Enforcing authorization policy and least privilege directly blocks user-controlled key tampering that bypasses access checks.

PR.IR-01 mostly match
prevents

Logical access controls prevent unauthorized data access that results from missing authorization checks on object references.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect missing authorization checks but does not prevent the weakness in production.

prevents

Information access restriction explicitly enforces that users may only retrieve data they are authorized to see, directly addressing user-controlled key bypass.

prevents

Access control policy directly requires enforcement of authorization rules that prevent unauthorized access via manipulated keys.

prevents

Managing access rights includes ensuring users can only access their own records and not bypass authorization by altering identifiers.

mitigates

Privileged access rights control restricts what data each user may access, mitigating direct object reference attacks.

prevents

Secure development lifecycle includes authorization design but does not itself implement runtime access checks.

References