log.c in Squid Analysis Report Generator (sarg) through 2.3.11 allows local privilege escalation. By default, it uses a fixed temporary directory /tmp/sarg. As the root user, sarg creates this directory or reuses an existing one in an insecure manner.

An attacker can pre-create the directory, and place symlinks in it (after winning a /tmp/sarg/denied.int_unsort race condition). The outcome will be corrupted or newly created files in privileged file system locations.