A privilege escalation flaw was found in Amanda 3.5.1 in which the backup user can acquire root privileges. The vulnerable component is the runtar SUID program, which is a wrapper to run /usr/bin/tar with specific arguments that are controllable by the attacker. This program mishandles the arguments passed to tar binary (it expects that the argument name and value are separated with a space; however, separating them with an equals sign is also supported),

Amanda 3.5.1 allows privilege escalation from the regular user backup to root. The SUID binary located at /lib/amanda/rundump will execute /usr/sbin/dump as root with controlled arguments from the attacker which may lead to escalation of privileges, denial of service, and information disclosure.