Linux kernel 2.4.1 through 2.4.19 sets root's NR_RESERVED_FILES limit to 10 files, which allows local users to cause a denial of service (resource exhaustion) by opening 10 setuid binaries.

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.

The experimental IP packet queuing feature in Netfilter / IPTables in Linux kernel 2.4 up to 2.4.19 and 2.5 up to 2.5.31, when a privileged process exits and network traffic is not being queued, may allow a later process with the same Process ID (PID) to access certain network traffic that would otherwise be restricted.

The Linux kernel 2.4.20 and earlier, and 2.5.x, when running on x86 systems, allows local users to cause a denial of service (hang) via the emulation mode, which does not properly clear TF and NT EFLAGs.

The Network Address Translation (NAT) capability for Netfilter ("iptables") 1.2.6a and earlier leaks translated IP addresses in ICMP error messages.

The ugidd RPC interface, by design, allows remote attackers to enumerate valid usernames by specifying arbitrary UIDs that ugidd maps to local user and group names.