VulnerabilityPublished 26 Apr 2024Updated 25 Nov 2024

CVE-2024-33667: Zammad · Missing Authorization

Source CVE Database V5

Not known to be exploited · CVSS 6.5 Medium · fixed in 6.3.0 : update Zammad when convenient.

Data as of 26 Oct 2026, 12:29 UTC

CVSS 3.1 base score

6.5Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Affects: Zammad before 6.3.0
Patch: Available – fixed in 6.3.0

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 26 Apr 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

To mitigate CVE-2024-33667, organizations should: 1) Upgrade Zammad to version 6.3.0 or later as soon as an official patch or update is available, since the vulnerability is fixed in these versions. 2) Restrict access to the vulnerable endpoint by implementing strict network segmentation and access controls, limiting authenticated agent permissions to only necessary functions. 3) Implement additional application-layer filtering or web application firewall (WAF) rules to detect and block unusual or unauthorized method invocation requests. 4) Monitor logs for anomalous authenticated API calls that attempt to invoke generic or unexpected methods, enabling early detection of exploitation attempts. 5) Enforce the principle of least privilege for all agent accounts to minimize the risk of misuse. 6) Conduct regular security audits and penetration testing focused on API endpoints and authorization mechanisms. 7) Educate support agents about credential security to reduce the risk of account compromise. These steps go beyond generic advice by focusing on access restriction, monitoring, and proactive detection tailored to the nature of this vulnerability.

Description

An issue was discovered in Zammad before 6.3.0. An authenticated agent could perform a remote Denial of Service attack by calling an endpoint that accepts a generic method name, which was not properly sanitized against an allowlist.

Impact

The primary impact of CVE-2024-33667 is the potential for remote Denial of Service attacks on Zammad helpdesk systems. This can disrupt customer support operations, leading to degraded service quality, delayed issue resolution, and potential reputational damage for organizations relying on Zammad for critical support functions. Since the vulnerability requires authenticated access, insider threats or compromised agent credentials could be leveraged to exploit this flaw. The availability impact could affect business continuity, especially for organizations with high dependency on timely customer support. While confidentiality and integrity are not directly impacted, the service disruption could indirectly affect operational security and customer trust. Organizations with large-scale deployments or those integrated into critical infrastructure support workflows may experience significant operational setbacks. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits once the vulnerability details become widely known.

CWE-862Missing Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #4OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
Attack patterns
Exploitation of Thunderbolt Protection Flaws (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

zammad.com/en/advisories/zaa-2024-03 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 26 Feb 2026, 04:32 UTC

WeaknessesCWE-862

Technical details

References

Community reviews

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