CVE 2009-0363
Multiple buffer overflows in (a) BarnOwl before 1.0.5 and (b) owl 2.1.11 allow remote attackers to execute arbitrary code via vectors involving (1) a crafted zcrypt message, related to zcrypt.c; (2) a reply command on a message with a Zephyr Cc: list, related to zwrite.c; and unspecified other use of the products.
See the 
CVE page on Mitre.org
for more details.
