diff -up fetchmail-6.3.8/sink.c.cve_2007_4565 fetchmail-6.3.8/sink.c
--- fetchmail-6.3.8/sink.c.cve_2007_4565 2007-03-30 00:45:17.000000000 +0200
+++ fetchmail-6.3.8/sink.c 2008-09-18 11:38:09.000000000 +0200
@@ -262,7 +262,7 @@ static int send_bouncemail(struct query
const char *md1 = "MAILER-DAEMON", *md2 = "MAILER-DAEMON@";
/* don't bounce in reply to undeliverable bounces */
- if (!msg->return_path[0] ||
+ if (!msg || !msg->return_path[0] ||
strcmp(msg->return_path, "<>") == 0 ||
strcasecmp(msg->return_path, md1) == 0 ||
strncasecmp(msg->return_path, md2, strlen(md2)) == 0)