Description
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.
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Metasploit 1 module
-
SSH Username Enumeration
auxiliary/scanner/ssh/ssh_enumusers
Exploit-DB 1
- Portable OpenSSH 3.6.1p-PAM/4.1-SuSE - Timing Attack EDB-3303 · remote · Feb 13, 2007 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- 25979 third-party-advisory
- 20061014 Re: yet another OpenSSH timing leak? mailing-list
- 20061009 yet another OpenSSH timing leak? mailing-list
- 20061010 Re: yet another OpenSSH timing leak? mailing-list
- ADV-2007-2545 vdb-entry
- 20418 vdb-entry
- 20061009 Re: yet another OpenSSH timing leak? mailing-list
- 32721 vdb-entry
- http://www.sybsecurity.com/hack-proventia-1.pdf