Re: CVE Request: dropbear sshd daemon 2013.59 release

[Matt Johnston <matt () ucc asn au>]

Hi all,

On Thu, Oct 10, 2013 at 03:27:07PM +0200, Marcus Meissner wrote:
> has this changes entry:
> - Limit the size of decompressed payloads, avoids memory exhaustion denial
>   of service 
>   https://secure.ucc.asn.au/hg/dropbear/rev/0bf76f54de6f

That's the right patch.

> It also has this changes entry which might need one:
> - Avoid disclosing existence of valid users through inconsistent delays
>   https://secure.ucc.asn.au/hg/dropbear/rev/a625f9e135a4

That should be https://secure.ucc.asn.au/hg/dropbear/rev/d7784616409a 
for the user disclosure.

I don't think the constant-time memcmp (a625f9e135a4) is
worth noting with a CVE. The packet HMAC is non-repeatable
for an attacker. The password crypt comparison has too long
a delay between tries, I think the majority of programs
would use straight strcmp().

Cheers,
Matt