telnetd in Heimdal 0.6.x before 0.6.6 and 0.7.x before 0.7.2 allows remote unauthenticated attackers to cause a denial of service (server crash) via unknown vectors that trigger a null dereference.
secunia.com/advisories/18894
secunia.com/advisories/18961
secunia.com/advisories/19005
securityreason.com/securityalert/449
www.debian.org/security/2006/dsa-977
www.osvdb.org/23244
www.securityfocus.com/archive/1/426043/100/0/threaded
www.securityfocus.com/bid/16676
www.stacken.kth.se/lists/heimdal-discuss/2006-02/msg00028.html
www.ubuntu.com/usn/usn-253-1
www.vupen.com/english/advisories/2006/0456
www.vupen.com/english/advisories/2006/0628
www.vupen.com/english/advisories/2006/0653
exchange.xforce.ibmcloud.com/vulnerabilities/24763