|From the Debian advisory:
An authenticated malicious client may request its catalog from the puppet
master, and cause the puppet master to execute arbitrary code. The puppet
master must be made to invoke the `template` or `inline_template` functions
during catalog compilation.
An authenticated malicious client may retrieve catalogs from the puppet
master that it is not authorized to access. Given a valid certificate and
private key, it is possible to construct an HTTP GET request that will
return a catalog for an arbitrary client.
An authenticated malicious client may execute arbitrary code on Puppet
agents that accept kick connections. Puppet agents are not vulnerable in
their default configuration. However, if the Puppet agent is configured to
listen for incoming connections, e.g. listen = true, and the agent's
auth.conf allows access to the `run` REST endpoint, then an authenticated
client can construct an HTTP PUT request to execute arbitrary code on the
agent. This issue is made worse by the fact that puppet agents typically
run as root.
A bug in Puppet allows SSL connections to be downgraded to SSLv2, which is
known to contain design flaw weaknesses This affects SSL connections
between puppet agents and master, as well as connections that puppet agents
make to third party servers that accept SSLv2 connections. Note that SSLv2
is disabled since OpenSSL 1.0.
An unauthenticated malicious client may send requests to the puppet master,
and have the master load code in an unsafe manner. It only affects users
whose puppet masters are running ruby 1.9.3 and above.
An authenticated malicious client may execute arbitrary code on the
puppet master in its default configuration. Given a valid certificate and
private key, a client can construct an HTTP PUT request that is authorized
to save the client's own report, but the request will actually cause the
puppet master to execute arbitrary code.
The default auth.conf allows an authenticated node to submit a report for
any other node, which is a problem for compliance. It has been made more
restrictive by default so that a node is only allowed to save its own