USN-1238-1: Puppet vulnerability

Releases

• Ubuntu 11.10
• Ubuntu 11.04
• Ubuntu 10.10
• Ubuntu 10.04

Packages

• puppet - Centralized configuration management

Details

It was discovered that Puppet incorrectly handled the non-default
"certdnsnames" option when generating certificates. If this setting was
added to puppet.conf, the puppet primary server’s DNS alt names were added
to the X.509 Subject Alternative Name field of all certificates, not just
the puppet primary server’s certificate. An attacker that has an incorrect
agent certificate in his possession can use it to impersonate the puppet
primary server in a machine-in-the-middle attack.

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 11.10

• puppet-common - 2.7.1-1ubuntu3.2

Ubuntu 11.04

• puppet-common - 2.6.4-2ubuntu2.5

Ubuntu 10.10

• puppet-common - 2.6.1-0ubuntu2.4

Ubuntu 10.04

• puppet-common - 0.25.4-2ubuntu6.5

In general, a standard system update will make all the necessary changes.

If your puppet primary server's puppet.conf file has ever contained the
"certdnsnames" setting, you must reissue your site certificates, or apply
another mitigation technique. Please see the upstream advisory for more
information:

http://puppetlabs.com/security/cve/cve-2011-3872/

References

• CVE-2011-3872