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.

IRC connection tracking helper module in the netfilter subsystem for Linux 2.4.18-pre9 and earlier does not properly set the mask for conntrack expectations for incoming DCC connections, which could allow remote attackers to bypass intended firewall restrictions.

The MAC module in Netfilter in Linux kernel 2.4.1 through 2.4.11, when configured to filter based on MAC addresses, allows remote attackers to bypass packet filters via small packets.

Linux kernel before 2.4.11pre3 in multiple Linux distributions allows local users to cause a denial of service (crash) by starting the core vmlinux kernel, possibly related to poor error checking during ELF loading.

Linux kernel 2.2.1 through 2.2.19, and 2.4.1 through 2.4.10, allows local users to cause a denial of service via a series of deeply nested symlinks, which causes the kernel to spend extra time when trying to access the link.

Multiple TCP implementations could allow remote attackers to cause a denial of service (bandwidth and CPU exhaustion) by setting the maximum segment size (MSS) to a very small number and requesting large amounts of data, which generates more packets with less TCP-level data that amplify network traffic and consume more server CPU to process.

ip_conntrack_ftp in the IPTables firewall for Linux 2.4 allows remote attackers to bypass access restrictions for an FTP server via a PORT command that lists an arbitrary IP address and port number, which is added to the RELATED table and allowed by the firewall.