Full Disclosure: Re: Using second gpg keyring may be misleading?

["Thor (Hammer of God)" <thor () hammerofgod com>]

What are you considering exploitable?  The untrusted/unverified "Master" key?

Timothy "Thor"  Mullen
www.hammerofgod.com
Thor's Microsoft Security Bible



-----Original Message-----
From: full-disclosure-bounces () lists grok org uk [mailto:full-disclosure-bounces () lists grok org uk] On Behalf Of 
Georgi Guninski
Sent: Thursday, June 14, 2012 7:18 AM
To: full-disclosure () lists grok org uk
Subject: [Full-disclosure] Using second gpg keyring may be misleading?

There is chance someone exploits this in apt-key...

Attached is a keyring and here is the output:

$rm -rf /home/joro2/.gnupg/ ; gpg --import /usr/share/keyrings/ubuntu-master-keyring.gpg ; gpg --check-sigs --keyring 
/tmp/sec3
gpg:               imported: 1  (RSA: 1)
gpg: no ultimately trusted keys found
/home/joro2/.gnupg/pubring.gpg
------------------------------
pub   4096R/3F272F5B 2007-11-09
uid                  Ubuntu Archive Master Signing Key <ftpmaster () ubuntu com>
sig!3        3F272F5B 2007-11-09  Ubuntu Archive Master Signing Key <ftpmaster () ubuntu com>

/tmp/sec3
---------
pub   1024R/B1C08810 2012-06-14
uid                  kkkkkkk5 <k () k>
sig!3        B1C08810 2012-06-14  [User ID not found]
sig!         3F272F5B 2012-06-14  Ubuntu Archive Master Signing Key <ftpmaster () ubuntu com>
sig!         3F272F5B 2012-06-14  Ubuntu Archive Master Signing Key <ftpmaster () ubuntu com>
sub   1024R/0354AE88 2012-06-14
sig!         B1C08810 2012-06-14  [User ID not found]
sub   2179R/3F272F5B 2012-06-14
sig!         B1C08810 2012-06-14  [User ID not found]

1 signature not checked due to a missing key


$rm -rf /home/joro2/.gnupg/ ; gpg --import /usr/share/keyrings/ubuntu-master-keyring.gpg ; gpg --no-default-keyring 
--check-sigs --keyring /tmp/sec3

gpg: Total number processed: 1
gpg:               imported: 1  (RSA: 1)
gpg: no ultimately trusted keys found
/tmp/sec3
---------
pub   1024R/B1C08810 2012-06-14
uid                  kkkkkkk5 <k () k>
sig!3        B1C08810 2012-06-14  kkkkkkk5 <k () k>
sig!         3F272F5B 2012-06-14  kkkkkkk5 <k () k>
sig!         3F272F5B 2012-06-14  kkkkkkk5 <k () k>
sub   1024R/0354AE88 2012-06-14
sig!         B1C08810 2012-06-14  kkkkkkk5 <k () k>
sub   2179R/3F272F5B 2012-06-14
sig!         B1C08810 2012-06-14  kkkkkkk5 <k () k>

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