CVE-2026-5082

Summary

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.

Affected Software

VendorProductVersion RangeStatus
TOKUHIROMAmon2::Plugin::Web::CSRFDefender7.00 <= 7.03affected

Weaknesses

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

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References