CyberSecBulletin
CVE-2025-40915NVD status: Deferred

Mojolicious::Plugin::CSRF: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

CVE-2025-40915 is a high-severity use of cryptographically weak pseudo-random number generator (PRNG) vulnerability in Mojolicious::Plugin::CSRF from GRYPHON, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Mojolicious::Plugin::CSRF versions: 1.03. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.29% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Mojolicious::Plugin::CSRF you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
GRYPHONMojolicious::Plugin::CSRF1.03Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
LowLimited modification of data is possible.
Availability
LowPerformance or availability is reduced.

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:L. Scored by CISA (ADP).

Official description

Mojolicious::Plugin::CSRF 1.03 for Perl uses a weak random number source for generating CSRF tokens. That version of the module generates tokens as an MD5 of the process id, the current time, and a single call to the built-in rand() function.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong.

How developers prevent this class of flaw

  • Use functions or hardware which use a hardware-based random number generation for all crypto. This is the recommended solution. Use CyptGenRandom on Windows, or hw_rand() on Linux.

More Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerabilities (CWE-338)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerabilities

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