Multiple vulnerabilities has been found and corrected in arj:

Jakub Wilk discovered that arj follows symlinks created during
unpacking of an arj archive. A remote attacker could use this flaw
to perform a directory traversal attack if a user or automated
system were tricked into processing a specially crafted arj archive
(CVE-2015-0556).

Jakub Wilk discovered that arj does not sufficiently protect from
directory traversal while unpacking an arj archive containing
file paths with multiple leading slashes. A remote attacker could
use this flaw to write to arbitrary files if a user or automated
system were tricked into processing a specially crafted arj archive
(CVE-2015-0557).

Jakub Wilk and Guillem Jover discovered a buffer overflow vulnerability
in arj. A remote attacker could use this flaw to cause an application
crash or, possibly, execute arbitrary code with the privileges of
the user running arj (CVE-2015-2782).

The updated packages provides a solution for these security issues.