Aavmker4.sys in avast! 4.8 through 4.8.1368.0 and 5.0 before 5.0.418.0 running on Windows 2000 and XP does not properly validate input to IOCTL 0xb2d60030, which allows local users to cause a denial of service (system crash) or execute arbitrary code to gain privileges via IOCTL requests using crafted kernel addresses that trigger memory corruption.

Heap-based buffer overflow in aswRdr.sys (aka the TDI RDR driver) in avast! Home and Professional 4.8.1356.0 allows local users to cause a denial of service (memory corruption) or possibly gain privileges via crafted arguments to IOCTL 0x80002024.