Checkmk: Incorrect Default Permissions
CVE-2022-33912 is a high-severity incorrect default permissions vulnerability in Checkmk, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected Checkmk versions: 1.6.0; 2.0.0; 2.1.0, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Checkmk you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on checkmk.com for workarounds and exact fixed builds.
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 2.0 | 7.2 | High | NVD |
Official description
A permission issue affects users that deployed the shipped version of the Checkmk Debian package. Packages created by the agent bakery (enterprise editions only) were not affected. Using the shipped version of the agents, the maintainer scripts located at /var/lib/dpkg/info/ will be owned by the user and the group with ID 1001. If such a user exists on the system, they can change the content of these files (which are then executed by root). This leads to a local privilege escalation on the monitored host. Version 1.6 through 1.6.9p29, version 2.0 through 2.0.0p26, version 2.1 through 2.1.0p3, and version 2.2.0i1 are affected.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Default Permissions
During installation, installed file permissions are set to allow anyone to modify those files.
How developers prevent this class of flaw
- The architecture needs to access and modification attributes for files to only those users who actually require those actions.
- 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. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
More Incorrect Default Permissions vulnerabilities (CWE-276)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
- checkmk.com/werk/14098Mitigation
Other vulnerabilities in Checkmk
- 9.4 Critical severity
- 9.4 Critical severity
- 9.4 Critical severity
- 7.1 High severity
- 8.6 High severity
- 7.8 High severity
Recent Incorrect Default Permissions vulnerabilities
- 7.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.2 High severity
- 7.8 High severity
- 7.8 High severity
Spotted an error? Tell us.