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.

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.

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.