libwww-perl-6.83 (Perl Module)

[Douglas R. Reno]

New point version

I got an email at 9:07AM from CPAN Security:

========================================================================
CVE-2026-8368                                        CPAN Security Group
========================================================================

        CVE ID:  CVE-2026-8368
  Distribution:  libwww-perl
      Versions:  before 6.83

      MetaCPAN:  https://metacpan.org/dist/libwww-perl
      VCS Repo:  https://github.com/libwww-perl/libwww-perl


LWP::UserAgent versions before 6.83 for Perl leak Authorization and
Proxy-Authorization headers on cross-origin redirects

Description
-----------
LWP::UserAgent versions before 6.83 for Perl leak Authorization and
Proxy-Authorization headers on cross-origin redirects.

On a 3xx response, the redirect handler strips only Host and Cookie
before issuing the follow-up request. Caller-supplied Authorization and
Proxy-Authorization headers are sent unchanged to the redirect target,
including across scheme, host, or port changes.

A redirect to an attacker controlled host therefore discloses the
caller's credentials to that host.

Problem types
-------------
- CWE-522 Insufficiently Protected Credentials

Solutions
---------
Upgrade to libwww-perl 6.83 or later.


References
----------
https://github.com/libwww-perl/libwww-perl/commit/9c4aeb6f2dd32f2b7eaf2d7827cade31ea6cb2c6.patch
https://metacpan.org/release/OALDERS/libwww-perl-6.83/changes
https://github.com/libwww-perl/libwww-perl/pull/512
https://github.com/libwww-perl/libwww-perl/pull/284

Timeline
--------
- 2026-05-11: Issue reported.
- 2026-05-12: libwww-perl 6.83 released with fix.

[Joe Locash]

6.83      2026-05-12 11:41:48Z
    - LWP::UserAgent now strips Authorization and Proxy-Authorization headers
      on cross-origin redirects (a different scheme, host, or port) to prevent
      credential leakage to the redirect target. Same-origin redirects retain
      credentials. Opt out with allow_credentialed_redirects => 1.
      CVE-2026-8368 reported by Kai Zen; PoC and initial patch by Stig
      Palmquist.
    - LWP::UserAgent now refuses https to http redirects by default to prevent
      leaking remaining request headers and bodies over plaintext. Opt in with
      allow_downgrade => 1. Related hardening alongside CVE-2026-8368; PoC by
      Stig Palmquist.

Fixed at b281d8bd70. Leaving open for SA.

[Douglas R. Reno]

SA-13.0-092 issued