Integer underflow in Doomsday (aka deng) 1.9.0-beta5.1 and earlier allows remote attackers to cause a denial of service (daemon crash) via a PKT_CHAT packet with a data length less than 3, which triggers an erroneous malloc, possibly related to the Sv_HandlePacket function in sv_main.c.
https://exchange.xforce.ibmcloud.com/vulnerabilities/36338
http://www.securityfocus.com/archive/1/478077/100/0/threaded
http://securityreason.com/securityalert/3084
http://security.gentoo.org/glsa/glsa-200802-02.xml
http://secunia.com/advisories/28821