Description
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.
Problem types
CWE-340 Generation of Predictable Numbers or Identifiers
CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator
Product status
7.00 (custom)
References
metacpan.org/.../lib/Amon2/Plugin/Web/CSRFDefender/Random.pm
metacpan.org/...M/Amon2-Plugin-Web-CSRFDefender-7.04/changes
www.cve.org/CVERecord?id=CVE-2025-15604