Format string vulnerability in screen 3.9.5 and earlier allows local users to gain root privileges via format characters in the vbell_msg initialization variable.
https://exchange.xforce.ibmcloud.com/vulnerabilities/5188
http://www.securityfocus.com/archive/1/80178
http://www.redhat.com/support/errata/RHSA-2000-058.html
http://www.novell.com/linux/security/advisories/adv6_draht_screen_txt.html
http://www.linux-mandrake.com/en/updates/MDKSA-2000-044.php3
http://archives.neohapsis.com/archives/bugtraq/2000-08/0530.html