A flaw in the update component of baserCMS allows an authenticated administrator to inject arbitrary operating system commands, resulting in complete code execution on the underlying server. This intrusion can compromise confidentiality, integrity, and availability of the hosted application and any data stored on the host. The weakness is an OS command injection (CWE‑78) and can be exploited to run any command the web server user has permission to execute.

All installations of baserCMS older than version 5.2.3 are vulnerable. The vulnerability exists in the core update functionality and affects any instance where administrators have access to execute updates on the system.

The vulnerability carries a CVSS score of 9.1, indicating severe risk when exploited. The EPSS score is below 1 %, suggesting a low probability of widespread exploitation at present, and it is not listed in the CISA KEV catalog. Attackers would need authenticated administrator privileges and then manipulate the update process to inject malicious commands via the unescaped exec() call.