Bug#729029: openssh: Memory corruption in AES-GCM support

[Moritz Muehlenhoff <jmm@inutil.org>]

Package: openssh
Severity: grave
Tags: security
Justification: user security hole

Please see http://www.openssh.com/txt/gcmrekey.adv

No CVE ID has been assigned yet.

AES-GCM support was introduced in 6.2, so oldstable and stable should
be fine (from http://www.openssh.com/txt/release-6.2):

| * ssh(1)/sshd(8): Added support for AES-GCM authenticated encryption in
|   SSH protocol 2. The new cipher is available as aes128-gcm@openssh.com
|   and aes256-gcm@openssh.com. It uses an identical packet format to the
|   AES-GCM mode specified in RFC 5647, but uses simpler and different
|   selection rules during key exchange.

Cheers,
        Moritz