arpwatch 2.1a15, as used by Red Hat, Debian, Fedora, and possibly others, does not properly drop supplementary groups, which might allow attackers to gain root privileges by leveraging other vulnerabilities in the daemon.
https://security.gentoo.org/glsa/201607-16
http://www.openwall.com/lists/oss-security/2012/05/25/5
http://www.openwall.com/lists/oss-security/2012/05/24/14
http://www.openwall.com/lists/oss-security/2012/05/24/13
http://www.openwall.com/lists/oss-security/2012/05/24/12
http://www.mandriva.com/security/advisories?name=MDVSA-2012:113
http://www.debian.org/security/2012/dsa-2481
http://lists.fedoraproject.org/pipermail/package-announce/2012-June/082569.html
http://lists.fedoraproject.org/pipermail/package-announce/2012-June/082565.html
http://lists.fedoraproject.org/pipermail/package-announce/2012-June/082553.html