VulnerabilityPublished 26 Apr 2024Updated 2 Aug 2024

CVE-2024-33666: zammad · Improper Access Control

Affects zammadSource CVE Database V5

Not known to be exploited · CVSS 8.6 High : upgrade to 6.3.0 soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

8.6High

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 6.3.0

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

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

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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

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

Upgrade zammad to 6.3.0.

Affected software

Product	Affected	Fixed in
RubyGemszammad`pkg:gem/zammad`Other threats	Affected <6.3.0	Fixed in 6.3.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2024-33666, organizations should: 1) Upgrade Zammad to version 6.3.0 or later as soon as it becomes available, as this version includes the fix for the improper access control issue. 2) In the interim, restrict API access by implementing network-level controls such as IP whitelisting or VPN access to limit exposure to trusted users only. 3) Review and tighten role-based access controls within Zammad to ensure customer users cannot access agent-only data fields. 4) Monitor API logs for unusual access patterns or attempts to retrieve time accounting data by unauthorized users. 5) If possible, disable or limit the API endpoints that expose ticket time accounting details until the patch is applied. 6) Educate internal teams about the sensitivity of time accounting data and the importance of promptly applying security updates. 7) Conduct regular audits of user permissions and API usage to detect and prevent privilege escalation or unauthorized data access. These steps go beyond generic advice by focusing on interim protective measures and proactive monitoring until the official patch is deployed.

Description

An issue was discovered in Zammad before 6.3.0. Users with customer access to a ticket could have accessed time accounting details of this ticket via the API. This data should be available only to agents.

Impact

The primary impact of CVE-2024-33666 is unauthorized disclosure of sensitive time accounting data within the Zammad ticketing system. This can compromise confidentiality by exposing internal operational metrics, such as time spent on tasks, which may reveal business processes, resource allocation, or billing information. Such exposure could facilitate social engineering, competitive intelligence gathering, or insider threats. Although the integrity and availability impacts are rated low, the confidentiality breach alone can have serious consequences, including loss of customer trust and regulatory compliance violations if sensitive data is mishandled. Organizations relying on Zammad for customer support and ticket management worldwide are at risk, particularly those handling sensitive or regulated data. The vulnerability's ease of exploitation without authentication increases the risk of automated or opportunistic attacks. While no active exploitation is currently known, the public disclosure and high CVSS score suggest that threat actors may develop exploits, increasing the urgency for mitigation.

CWE-284Improper Access Control (opens in a new tab)
Pillar weaknessCWE Top 25 (2025): #19OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Operation
Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
OWASP Cheat Sheets
Docker Security (opens in a new tab)
Third Party Javascript Management (opens in a new tab)
Virtual Patching (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V1.4.4 (opens in a new tab)
V1.4.5 (opens in a new tab)
V1.10.1 (opens in a new tab)
Attack patterns
Embedding Scripts within Scripts (opens in a new tab)
Modification of Windows Service Configuration (opens in a new tab)
Malicious Root Certificate (opens in a new tab)
Intent Spoof (opens in a new tab)
WebView Exposure (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

zammad.com/en/advisories/zaa-2024-01 (opens in a new tab)

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

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

WeaknessesCWE-284

Technical details

References

Community reviews

Related threats