Portable OpenSSH <= 3.6.1p-PAM / 4.1-SUSE Timing Attack Exploit

raptor_sshtime - [Open]SSH remote timing attack exploit
Copyright (c) 2006 Marco Ivaldi

OpenSSH-portable 3.6.1p1 and earlier with PAM support enabled immediately sends an error message when a user does not exist, which allows remote attackers to determine valid usernames via a timing attack (CVE-2003-0190).

OpenSSH portable 4.1 on SUSE Linux, and possibly other platforms and versions, and possibly under limited configurations, allows remote attackers to determine valid usernames via timing discrepancies in which responses take longer for valid usernames than invalid ones, as demonstrated by sshtime.

NOTE: as of 20061014, it appears that this issue is dependent on the use of manually-set passwords that causes delays when processing /etc/shadow due to an increased number of rounds (CVE-2006-5229).

This is a simple shell script based on expect meant to remotely analyze timing differences in sshd "Permission denied" replies. Depending on OpenSSH version and configuration, it may lead to disclosure of valid usernames.

http://www.milw0rm.com/exploits/3303