Net::Statsd::Lite versions before 0.9.0 for Perl allowed metric injections. The metric names were not checked for newlines, colons or pipes. Metrics generated from untrusted sources could inject additional statsd metrics.
https://metacpan.org/release/RRWO/Net-Statsd-Lite-v0.9.0/changes
https://github.com/robrwo/Net-Statsd-Lite/commit/e1a8ab866d75c2827982134e9cf7e51a7f771153.patch