Bug 675254 (CVE-2011-0539)

Summary: CVE-2011-0539 OpenSSH: legacy certificate generation information leak
Product: [Other] Security Response Reporter: Josh Bressers <bressers>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: jchadima, wnefal+redhatbugzilla
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
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Clone Of: Environment:
Last Closed: 2011-07-01 14:13:25 UTC Type: ---
Regression: --- Mount Type: ---
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Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 718133    
Bug Blocks:    

Description Josh Bressers 2011-02-04 17:59:20 UTC 
From the upstream advisory:
http://www.openssh.com/txt/legacy-cert.adv

        When generating legacy *-cert-v00 certificates,
        the nonce field was not being correctly filled with random
        data but was left uninitialised, containing the contents of
        the stack.

        The contents of the stack at this point in ssh-keygen's
        execution do not appear to leak the CA private key or other
        sensitive data, but this possibility cannot be excluded on
        all platforms and library versions.

        If certificates are generated using user-specified contents
        (as opposed to the CA specifying all fields) then they will
        be less resistant to hash collision attacks. Fortunately,
        such attacks are not currently considered practical for the
        SHA family of hashes used to sign these certificates.

This only affected OpenSSH versions 5.6 and 5.7, which Red Hat does not
currently ship.
Comment 1 Tomas Hoger 2011-07-01 07:01:38 UTC 
Created openssh tracking bugs for this issue

Affects: fedora-15 [bug 718133]
Comment 2 Tomas Hoger 2011-07-01 14:13:25 UTC 
Statement:

Not vulnerable. This issue did not affect the versions of openssh as shipped with Red Hat Enterprise Linux 4, 5, or 6.