CVE-2011-0633
The Net::HTTPS module in libwww-perl (LWP) before 6.00, as used in WWW::Mechanize, LWP::UserAgent...
CVE-2011-0633 is a medium vulnerability (CVSS 4.3) in Gisle Aas Libwww-perl, published May 13, 2011. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 4.25%, the 91st percentile. Fixed in libwww-perl 6.01-1.
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.
Exploit likelihood
What each source reports
NVD Score used
4.3
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.
- Record
CVE-2011-0633- CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2011-0633- Updated
- 2026-11-02
EUVDEUVD-2011-0651 No score
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.
- Record
EUVD-2011-0651- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-3fhh-g5rg-6jpm No score
The Net::HTTPS module in libwww-perl (LWP) before 6.00, as used in WWW::Mechanize, LWP::UserAgent...
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.
- Record
GHSA-3fhh-g5rg-6jpm- Weakness
- CWE-20
- Updated
- 2026-11-02
OSV No score
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.
- Record
CVE-2011-0633- Updated
- 2026-11-02
OSVDEBIAN-CVE-2011-0633 No score
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.
- Record
DEBIAN-CVE-2011-0633- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libwww-perlDebian:12 |
before 6.01-1 | 6.01-1 |
libwww-perlDebian:13 |
before 6.01-1 | 6.01-1 |
libwww-perlDebian:14 |
before 6.01-1 | 6.01-1 |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-03 | aliases | EUVD |
| 2026-11-02 | created | CVE List, GitHub Advisories, NVD, OSV |
References
vttynotes.blogspot.com/2010/12/man-in-middle-fun-with-perl-lwp.html
cpansearch.perl.org/src/GAAS/libwww-perl-6.02/Changes
vttynotes.blogspot.com/2011/03/quick-note-on-lwp-and-perl-security-cve.html
nvd.nist.gov/vuln/detail/CVE-2011-0633
github.com/advisories/GHSA-3fhh-g5rg-6jpm
security-tracker.debian.org/tracker/CVE-2011-0633