The nvcoaft51 driver in Norman Virus Control (NVC) 5.82 uses weak permissions (unrestricted write access) for the NvcOa device, which allows local users to gain privileges by (1) triggering a buffer overflow in a kernel pool via a string argument to ioctl 0xBF67201C; or by (2) sending a crafted KEVENT structure through ioctl 0xBF672028 to overwrite arbitrary memory locations.

The OLE2 parsing in Norman Antivirus before 5.91.02 allows remote attackers to cause a denial of service via a crafted DOC file that triggers a divide-by-zero error.

Multiple buffer overflows in Norman Antivirus 5.90 allow remote attackers to execute arbitrary code via a crafted (1) ACE or (2) LZH file, resulting from an "integer cast around."

Multiple interpretation error in Norman 5.81 with the 5.83.02 engine allows remote attackers to bypass virus scanning via a file such as BAT, HTML, and EML with an "MZ" magic byte sequence which is normally associated with EXE, which causes the file to be treated as a safe type that could still be executed as a dangerous file type by applications on the end system, as demonstrated by a "triple headed" program that contains EXE, EML, and HTML content, aka the "magic byte bug."