Malicious plugin can abort data collection for a node

[cbiedl]

Hi there,

using "multigraph" as a multigraph service name is not accepted by
Munin::Master::Node. The check however dies (in config) or croaks
(in fetch), causing in the connection being dropped and no data
gathered for that node. That's a bit harsh.

The patch below lowers that situation to two error messages.

Impact is rather small as this affects the data for that node itself.
A malicious plugin still does harm, but if an evil guy is able to
control which plugins are run on a node, no longer collecting munin
data for that one is not one of the bigger concerns.

Cheers,

Christoph

[cbiedl]

This was assigned CVE-2013-6359 and fixed in 2.0.18