The auth_parse_options function in auth-options.c in sshd in OpenSSH before 5.7 provides debug messages containing authorized_keys command options, which allows remote authenticated users to obtain potentially sensitive information by reading these messages, as demonstrated by the shared user account required by Gitolite. NOTE: this can cross privilege boundaries because a user account may intentionally have no shell or filesystem access, and therefore may have no supported way to read an authorized_keys file in its own home directory.
https://exchange.xforce.ibmcloud.com/vulnerabilities/72756
http://www.securityfocus.com/bid/51702
http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/auth-options.c.diff?r1=1.53%3Br2=1.54
http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/auth-options.c
http://openwall.com/lists/oss-security/2012/01/27/4
http://openwall.com/lists/oss-security/2012/01/27/1
http://openwall.com/lists/oss-security/2012/01/26/16
http://openwall.com/lists/oss-security/2012/01/26/15
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10673