oss-security - Re: CVE request: perl-IO-Socket-SSL certificate hostname compare bug

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Date: Sat, 29 Aug 2009 20:45:53 +0200
From: Steffen Ullrich <Steffen_Ullrich@...ua.de>
To: oss-security@...ts.openwall.com,
        "Steven M. Christey" <coley@...us.mitre.org>
Subject: Re: CVE request: perl-IO-Socket-SSL certificate hostname compare bug

Hi,

Just to make you able to classify the problem a bit more:
The fix is important but the impact of the problem is in my opinion currently minor,
because
- the feature to help checking the hostname against the certificate is fairly new
- in former times the apps/modules using IO::Socket::SSL had to implement
  the checking by itself (using the appropriate logic, which differs between
  various protocols).
- most did not implement any checking at all or implemented a limited or wrong check
- therefore I added the checks, where the app only has to decide how the check
  has to be done
- most apps/modules don't even do this simple thing yet, so that this buggy
  feature was not used

That means, that it only impacts apps/modules which depend on this feature
and there are only few (or none) of these apps. But it would probably be nice
to add a note to the CVE that apps/modules should start to implement proper 
certificate checking and that it got easier with newer IO::Socket::SSL
versions.

Regards,
Steffen (Maintainer of IO::Socket::SSL)


On Fri, Aug 28, 2009 at 09:20:22AM +0200, Ludwig Nussel <ludwig.nussel@...e.de> wrote:
> Hi,
> 
> IO-Socket-SSL was released a while ago with a security fix:
> 
> http://cpansearch.perl.org/src/SULLR/IO-Socket-SSL-1.30/Changes
> v1.26 2009.07.03
> - SECURITY BUGFIX! 
>   fix Bug in verify_hostname_of_cert where it matched only the prefix for 
>   the hostname when no wildcard was given, e.g. www.example.org matched
>   against a certificate with name www.exam in it
>   Thanks to MLEHMANN for reporting
> 
> cu
> Ludwig
> 
> -- 
>  (o_   Ludwig Nussel
>  //\   
>  V_/_  http://www.suse.de/
> SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nuernberg)

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