The SSH USERAUTH CHANGE REQUEST feature in SSH Tectia Server 6.0.4 through 6.0.20, 6.1.0 through 6.1.12, 6.2.0 through 6.2.5, and 6.3.0 through 6.3.2 on UNIX and Linux, when old-style password authentication is enabled, allows remote attackers to bypass authentication via a crafted session involving entry of blank passwords, as demonstrated by a root login session from a modified OpenSSH client with an added input_userauth_passwd_changereq call in sshconnect2.c.

References

• https://nvd.nist.gov/vuln/detail/CVE-2012-5975
• https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/unix/ssh/tectia_passwd_changereq.rb
• http://archives.neohapsis.com/archives/fulldisclosure/2012-12/0013.html
• http://archives.neohapsis.com/archives/fulldisclosure/2012-12/0065.html
• http://www.exploit-db.com/exploits/23082