Freebsd : Security Vulnerabilities, CVEs, Published In 2001 (Denial of service)

telnetd in FreeBSD 4.2 and earlier, and possibly other operating systems, allows remote attackers to cause a denial of service by specifying an arbitrary large file in the TERMCAP environmental variable, which consumes resources as the server processes the file.

procfs in FreeBSD and possibly other operating systems allows local users to cause a denial of service by calling mmap on the process' own mem file, which causes the kernel to hang.

time server daemon timed allows remote attackers to cause a denial of service via malformed packets.

rwho daemon rwhod in FreeBSD 4.2 and earlier, and possibly other operating systems, allows remote attackers to cause a denial of service via malformed packets with a short length.

NetBSD 1.5 and earlier and FreeBSD 4.3 and earlier allows a remote attacker to cause a denial of service by sending a large number of IP fragments to the machine, exhausting the mbuf pool.

SGI IRIX 6.5 through 6.5.12f and possibly earlier versions, and FreeBSD 3.0, allows remote attackers to cause a denial of service via a malformed IGMP multicast packet with a small response delay.

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.