GLSA-200611-06 : OpenSSH: Multiple Denial of Service vulnerabilities
High Nessus Plugin ID 23671
SynopsisThe remote Gentoo host is missing one or more security-related patches.
DescriptionThe remote host is affected by the vulnerability described in GLSA-200611-06 (OpenSSH: Multiple Denial of Service vulnerabilities)
Tavis Ormandy of the Google Security Team has discovered a pre-authentication vulnerability, causing sshd to spin until the login grace time has been expired. Mark Dowd found an unsafe signal handler that was vulnerable to a race condition. It has also been discovered that when GSSAPI authentication is enabled, GSSAPI will in certain cases incorrectly abort.
The pre-authentication and signal handler vulnerabilities can cause a Denial of Service in OpenSSH. The vulnerability in the GSSAPI authentication abort could be used to determine the validity of usernames on some platforms.
There is no known workaround at this time.
SolutionAll OpenSSH users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose '>=net-misc/openssh-4.4_p1-r5'