CVE-2007-5636

Buffer overflow in the Nortel UNIStim IP Softphone 2050 allows remote attackers to cause a denial of service (application abort) and possibly execute arbitrary code via a flood of invalid characters to the RTCP port (5678/udp) that triggers a Windows error message, aka "extraneous messaging."

CVE-2007-5639

The Nortel UNIStim IP Softphone 2050, IP Phone 1140E, and other Nortel IP Phone, Mobile Voice Client, and WLAN Handsets products allow remote attackers to cause a denial of service (device hang) via a flood of Mute and UnMute messages that have a spoofed source IP address for the Signaling Server.