Red Hat Bugzilla – Full Text Bug Listing
|Summary:||CVE-2006-5051 unsafe GSSAPI signal handler|
|Product:||[Fedora] Fedora||Reporter:||Josh Bressers <bressers>|
|Component:||openssh||Assignee:||Tomas Mraz <tmraz>|
|Status:||CLOSED ERRATA||QA Contact:||Brian Brock <bbrock>|
|Fixed In Version:||Doc Type:||Bug Fix|
|Doc Text:||Story Points:||---|
|Last Closed:||2006-10-06 11:26:14 EDT||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
Description Josh Bressers 2006-09-28 14:36:26 EDT
+++ This bug was initially created as a clone of Bug #208347 +++ OpenSSH 4.4 was released and mentions: * Fix an unsafe signal hander reported by Mark Dowd. The signal handler was vulnerable to a race condition that could be exploited to perform a pre-authentication denial of service. On portable OpenSSH, this vulnerability could theoretically lead to pre-authentication remote code execution if GSSAPI authentication is enabled, but the likelihood of successful exploitation appears remote. -- Additional comment from email@example.com on 2006-09-28 11:17 EST -- I've done some analysis of this issue and received a mail from Mark Dowd regarding this vulnerability. The upstream details are misleading. The problem is that the signal handling in openssh does quite a lot and can introduce a race condition during cleanup. This flaw could possibly cause a double free condition within the kerberos cleanup code. The GSSAPI code is completely harmless, upstream calling this issue a GSSAPI issue leads me to believe they did not analyze, not try to understand this issue. There is also PAM cleanup code which is executed. This PAM source hasn't been investigated so the possible outcome is currently unknown. Red Hat will be fixing this issue due to the incredible complexity and possible danger. This is a case of better safe than sorry.
Comment 1 Fedora Update System 2006-10-03 16:02:37 EDT
openssh-4.3p2-4.10 has been pushed for fc5, which should resolve this issue. If these problems are still present in this version, then please make note of it in this bug report.