OpenVPN 2.x before 2.0.4, when running in TCP mode, allows remote attackers to cause a denial of service (segmentation fault) by forcing the accept function call to return an error status, which leads to a null dereference in an exception handler.
http://www.securityfocus.com/bid/15270
http://www.securityfocus.com/archive/1/415487
http://www.novell.com/linux/security/advisories/2005_25_sr.html
http://www.gentoo.org/security/en/glsa/glsa-200511-07.xml
http://www.debian.org/security/2005/dsa-885
http://secunia.com/advisories/17480
http://secunia.com/advisories/17452
http://secunia.com/advisories/17447