Red Hat Bugzilla – Bug 675254
CVE-2011-0539 OpenSSH: legacy certificate generation information leak
Last modified: 2011-07-01 10:13:25 EDT
From the upstream advisory:
When generating legacy *-firstname.lastname@example.org certificates,
the nonce field was not being correctly filled with random
data but was left uninitialised, containing the contents of
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
Created openssh tracking bugs for this issue
Affects: fedora-15 [bug 718133]
Not vulnerable. This issue did not affect the versions of openssh as shipped with Red Hat Enterprise Linux 4, 5, or 6.