Broad access controls could allow site users to directly interact with the system Apache installation when providing the reverse proxy configurations for Tribe29's Checkmk <= 2.1.0p6, Checkmk <= 2.0.0p27, and all versions of Checkmk 1.6.0 (EOL) allowing an attacker to perform remote code execution with root privileges on the underlying host.
CWE-829, CWE-829