GLSA Advocate
Joined: 12 May 2004 Posts: 2663
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Posted: Mon Nov 13, 2006 11:26 pm Post subject: [ GLSA 200611-06 ] OpenSSH: Multiple Denial of Service vulne |
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Gentoo Linux Security Advisory
Title: OpenSSH: Multiple Denial of Service vulnerabilities (GLSA 200611-06)
Severity: normal
Exploitable: remote
Date: November 13, 2006
Bug(s): #149502
ID: 200611-06
Synopsis
Several Denial of Service vulnerabilities have been identified in OpenSSH.
Background
OpenSSH is a complete SSH protocol version 1.3, 1.5 and 2.0 implementation and includes sftp client and server support.
Affected Packages
Package: net-misc/openssh
Vulnerable: < 4.4_p1-r5
Unaffected: >= 4.4_p1-r5
Architectures: All supported architectures
Description
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.
Impact
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.
Workaround
There is no known workaround at this time.
Resolution
All OpenSSH users should upgrade to the latest version: Code: | # emerge --sync
# emerge --ask --oneshot --verbose ">=net-misc/openssh-4.4_p1-r5" |
References
CVE-2006-5051
CVE-2006-5052
OpenSSH Security Advisory |
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