CVE-2009-0641: Undefined Security Weakness

systerm.c in telnetd in FreeBSD 7.0-RELEASE and other 7.x versions deletes dangerous environment variables with a method that was valid only in older FreeBSD distributions, which might allow remote attackers to execute arbitrary code by passing a crafted environment variable from a telnet client,...

FreeBSD telnetd sys_term.c Environment Variable Handling Privilege Escalation (FreeBSD-SA-09:05)

A flaw in the environment-handling code used by the telnet server running on the remote host fails to scrub the environment of variables such as 'LDPRELOAD' before calling the login program. An attacker who can place an arbitrary library on the remote host, either as a local user or remotely...