Zammad: Improper Restriction of Excessive Authentication Attempts
CVE-2022-35490 is a critical-severity improper restriction of excessive authentication attempts vulnerability in Zammad, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Zammad versions: 5.2.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.91% chance of exploitation within 30 days, higher than 61% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Zammad you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on zammad.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
Official description
Zammad 5.2.0 is vulnerable to privilege escalation. Zammad has a prevention against brute-force attacks trying to guess login credentials. After a configurable amount of attempts, users are invalidated and logins prevented. An attacker might work around this prevention, enabling them to send more than the configured amount of requests before the user invalidation takes place.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Restriction of Excessive Authentication Attempts
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.
How developers prevent this class of flaw
- Common protection mechanisms include: Disconnecting the user after a small number of failed attempts Implementing a timeout Locking out a targeted account Requiring a computational task on the user's part.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
More Improper Restriction of Excessive Authentication Attempts vulnerabilities (CWE-307)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Zammad
- 7.8 High severity
- 9.8 Critical severity
Zammad GmbH Zammad Session Fixation Exploited
- 7.1 High severity
- 7.1 High severity
- 9.1 Critical severity
- 8.6 High severity
Recent Improper Restriction of Excessive Authentication Attempts vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
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