The encrypted loop device in Linux kernel 2.4.10 and earlier does not authenticate the entity that is encrypting data, which allows local users to modify encrypted data without knowing the key.

ptrace in Linux 2.2.x through 2.2.19, and 2.4.x through 2.4.9, allows local users to gain root privileges by running ptrace on a setuid or setgid program that itself calls an unprivileged program, such as newgrp.

ICMP messages to broadcast addresses are allowed, allowing for a Smurf attack that can cause a denial of service.