Metrics::Any::Adapter::SignalFx versions before 0.04 for Perl does not protect against metric injections.
The statsd protocol (and extensions such as dogstatsd) allow mutiple metrics,separated by newlines, to be sent per packet.
Metrics::Any::Adapter::SignalFx which extends Metrics::Any::Adapter::Statsd, which has a similar vulnerability.
In addition, the _labels function does not check tags labels newlines or statsd control characters. The labels can be used for metric injections.
Upgrade to v0.04 or later.