Checkmk Permission Enforcement Issues

Checkmk contains an improper permission enforcement vulnerability in the agent-receiver/register_existing endpoint that allows authenticated users to enumerate existing hosts by observing differential HTTP response codes, enabling information disclosure. This affects Checkmk versions 2.4.0 before 2.4.0p23, 2.3.0 before 2.3.0p43, and the end-of-life 2.2.0 branch. While not currently listed as actively exploited in known vulnerability catalogs, the low CVSS score of 5.3 reflects limited confidentiality impact and the requirement for prior authentication, though the straightforward nature of the enumeration technique presents moderate real-world risk.

Checkmk contains an improper permission enforcement vulnerability in the deploy_agent endpoint that allows unauthenticated users to enumerate existing hosts by analyzing differential HTTP response codes, resulting in information disclosure. The vulnerability affects Checkmk versions 2.4.0 before 2.4.0p23, 2.3.0 before 2.3.0p43, and end-of-life version 2.2.0, with a CVSS score of 6.3 indicating moderate severity. An attacker with network access can passively discover the infrastructure topology without authentication, though no known active exploitation or public POC has been confirmed at this time.