OpenSSH 5.6 and earlier, when J-PAKE is enabled, does not properly validate the public parameters in the J-PAKE protocol, which allows remote attackers to bypass the need for knowledge of the shared secret, and successfully authenticate, by sending crafted values in each round of the protocol, a related issue to CVE-2010-4252.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12338
https://github.com/seb-m/jpake
https://bugzilla.redhat.com/show_bug.cgi?id=659297
http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/jpake.c.diff?r1=1.4%3Br2=1.5%3Bf=h
http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/jpake.c#rev1.5
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10673