The prescan function in Sendmail 8.12.9 allows remote attackers to execute arbitrary code via buffer overflow attacks, as demonstrated using the parseaddr function in parseaddr.c.

Integer overflow in the xdrmem_getbytes() function, and possibly other functions, of XDR (external data representation) libraries derived from SunRPC, including libnsl, libc, glibc, and dietlibc, allows remote attackers to execute arbitrary code via certain integer values in length fields, a different vulnerability than CVE-2002-0391.

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.

ICMP messages to broadcast addresses are allowed, allowing for a Smurf attack that can cause a denial of service.