Improper Input Validation

Summary

The Net::HTTPS module in libwww-perl (LWP) prior to 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.