What’s Vulnerable › Vulnerabilities

CVE-2011-0633

• Severity: medium (CVSS 4.3 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 4.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2011-05-13 · updated 2026-06-16
• Weakness: CWE-20

Description

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.

Affected products

• Gisle Aas Libwww-Perl: 0.01, 0.02, 0.03, 0.04, 5.00, 5.01 (+116)
• Search.Cpan Libwww-Perl: through 5.837; 5.40_01

References

• http://cpansearch.perl.org/src/GAAS/libwww-perl-6.02/Changes
• http://vttynotes.blogspot.com/2010/12/man-in-middle-fun-with-perl-lwp.html
• http://vttynotes.blogspot.com/2011/03/quick-note-on-lwp-and-perl-security-cve.html
• http://cpansearch.perl.org/src/GAAS/libwww-perl-6.02/Changes
• http://vttynotes.blogspot.com/2010/12/man-in-middle-fun-with-perl-lwp.html
• http://vttynotes.blogspot.com/2011/03/quick-note-on-lwp-and-perl-security-cve.html

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