ifconfig, when used on the Linux kernel 2.2 and later, does not report when the network interface is in promiscuous mode if it was put in promiscuous mode using PACKET_MR_PROMISC, which could allow attackers to sniff the network without detection, as demonstrated using libpcap.

Linux kernel 2.2.x allows local users to cause a denial of service (crash) by using the mmap() function with a PROT_READ parameter to access non-readable memory pages through the /proc/pid/mem interface.

The d_path function in Linux kernel 2.2.20 and earlier, and 2.4.18 and earlier, truncates long pathnames without generating an error, which could allow local users to force programs to perform inappropriate operations on the wrong directories.

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.