The Net::HTTPS module in libwww-perl (LWP) before 6.00, as used in WWW::Mechanize, LWP::UserAgent, and other products, when running in environments that do not set the If-SSL-Cert-Subject header, does not enable full validation of SSL certificates by default, which allows remote attackers to spoof servers via man-in-the-middle (MITM) attacks involving hostnames that are not properly validated. NOTE: it could be argued that this is a design limitation of the Net::HTTPS API, and separate implementations should be independently assigned CVE identifiers for not working around this limitation. However, because this API was modified within LWP, a single CVE identifier has been assigned.
http://vttynotes.blogspot.com/2011/03/quick-note-on-lwp-and-perl-security-cve.html
http://vttynotes.blogspot.com/2010/12/man-in-middle-fun-with-perl-lwp.html
http://cpansearch.perl.org/src/GAAS/libwww-perl-6.02/Changes