The on-demand scanning in Symantec AntiVirus 10.0.x and 10.1.x before MR9 AntiVirus 10.2.x and Client Security 3.0.x and 3.1.x before MR9 when Tamper protection is disabled allows remote attackers to cause a denial of service (prevention of on-demand scanning) via \specific events\ that prevent the user from having read access to unspecified resources.