CVE 2009-2651
main/rtp.c in Asterisk Open Source 1.6.1 before 1.6.1.2 allows remote attackers to cause a denial of service (crash) via an RTP text frame without a certain delimiter, which triggers a NULL pointer dereference and the subsequent calculation of an invalid pointer.
See the 
CVE page on Mitre.org
for more details.
