Symantec Scan Engine 5.0.0.24, and possibly other versions before 5.1.0.7, uses the same private DSA key for each installation, which allows remote attackers to conduct man-in-the-middle attacks and decrypt communications.
https://exchange.xforce.ibmcloud.com/vulnerabilities/25973
http://www.vupen.com/english/advisories/2006/1464
http://www.symantec.com/avcenter/security/Content/2006.04.21.html
http://www.securityfocus.com/bid/17637
http://www.securityfocus.com/archive/1/431734/100/0/threaded
http://www.securityfocus.com/archive/1/431725/100/0/threaded
http://securitytracker.com/id?1015974
http://secunia.com/advisories/19734
http://archives.neohapsis.com/archives/vulnwatch/2006-q2/0011.html