High · published August 11, 2026
A flaw was found in MRTG. When the MRTG daemon is started as a root user and subsequently drops privileges, a local, low-privileged attacker can exploit a symbolic link (symlink) following vulnerability. By influencing or pre-placing a symlink in the process ID (PID) file path, the attacker can trick the root process into changing the ownership of an arbitrary existing file to the daemon user. This can lead to local privilege escalation, allowing unauthorized access to or modification of sensitive files.