The (1) VetMONNT.sys and (2) VetFDDNT.sys drivers in CA Anti-Virus 2007 8.1, Anti-Virus for Vista Beta 8.2, and CA Internet Security Suite 2007 v3.0 do not properly handle NULL buffers, which allows local users with administrative access to cause a denial of service (system crash) via certain IOCTLs.