Common Vulnerabilities and Exposures assigned an identifier CVE-2010-4478 to the following vulnerability: 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. References: http://seb.dbzteam.org/crypto/jpake-session-key-retrieval.pdf https://github.com/seb-m/jpake http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/jpake.c#rev1.5
As noted in Sébastien Martini's paper, J-PAKE support in OpenSSH is experimental work-in-progress. It's not enabled in Red Hat Enterprise Linux and Fedora openssh packages. Statement: Not vulnerable. This issue did not affect the versions of openssh as shipped with Red Hat Enterprise Linux 4, 5, or 6.