CVE-2026-5082 PUBLISHED

Amon2::Plugin::Web::CSRFDefender versions from 7.00 through 7.03 for Perl generate an insecure session id.

The generate_session_id function will attempt to read bytes from the /dev/urandom device, but if that is unavailable then it generates bytes using SHA-1 hash seeded with the built-in rand() function, the PID, and the high resolution epoch time. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.

Amon2::Plugin::Web::CSRFDefender versions before 7.00 were part of Amon2, which was vulnerable to insecure session ids due to CVE-2025-15604.

Note that the author has deprecated this module.

Upgrade to Amon2::Plugin::Web::CSRFDefender version 7.04 or later.

• https://metacpan.org/release/TOKUHIROM/Amon2-Plugin-Web-CSRFDefender-7.03/source/lib/Amon2/Plugin/Web/CSRFDefender/Random.pm
• https://metacpan.org/release/TOKUHIROM/Amon2-Plugin-Web-CSRFDefender-7.04/changes
• https://www.cve.org/CVERecord?id=CVE-2025-15604

• CWE-340 Generation of Predictable Numbers or Identifiers CWE
• CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator CWE

• CAPEC-62 Cross Site Request Forgery