Ubuntu: USN-2916-1 (CVE-2016-2381): Perl vulnerabilities

It was discovered that Perl incorrectly handled certain regular expressions
with an invalid backreference. An attacker could use this issue to cause
Perl to crash, resulting in a denial of service, or possibly execute
arbitrary code. (CVE-2013-7422)

Markus Vervier discovered that Perl incorrectly handled nesting in the
Data::Dumper module. An attacker could use this issue to cause Perl to
consume memory and crash, resulting in a denial of service. (CVE-2014-4330)

Stephane Chazelas discovered that Perl incorrectly handled duplicate
environment variables. An attacker could possibly use this issue to bypass
the taint protection mechanism. (CVE-2016-2381)