Cyber Resilience

CVE-2024-33668

Access Control in Zammad 6.2.0 – 6.3.0

Published
26 April 2024
Modified
15 April 2025
Patch / advisory
CVSS Score v3.1 9.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0044 37th percentile
Risk Priority 67 floored blend · peak EPSS

Summary

CVE-2024-33668 is a critical-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Zammad Zammad. Its CVSS base score is 9.1 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 37th 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

An issue was discovered in Zammad before 6.3.0. The Zammad Upload Cache uses insecure, partially guessable FormIDs to identify content. An attacker could try to brute force them to upload malicious content to article drafts they have no access to.

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-2025-32358Same product: Zammad Zammad
CVE-2026-34719Same product: Zammad Zammad
CVE-2026-34721Same product: Zammad Zammad
CVE-2025-32359Same product: Zammad Zammad
CVE-2024-33667Same product: Zammad Zammad
CVE-2026-34722Same product: Zammad Zammad
CVE-2026-34782Same product: Zammad Zammad
CVE-2025-32357Same product: Zammad Zammad
CVE-2023-31597Same product: Zammad Zammad
CVE-2023-50457Same product: Zammad Zammad

Affected Assets

zammad
zammad
6.3.0 · 6.2.0 — 6.3.0

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