Home/CVE/Mojolicious::Plugin::CaptchaPNG version 1.05 for Perl uses a weak random number source for generating the captcha. That
CVE

CVE-2025-40916

Mojolicious::Plugin::CaptchaPNG version 1.05 for Perl uses a weak random number source for generating the captcha. That

Mojolicious::Plugin::CaptchaPNG version 1.05 for Perl uses a weak random number source for generating the captcha. That version uses the built-in rand() function for generating the captcha text as well as image noise, which is insecure.

CRITICAL · CVSS 9.1 EPSS 0.00284
Schedule remediation
  • SSVC automatable: yes - attacks can be scripted at scale
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-338Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
CWE-804Guessable CAPTCHA
▣

Scoring & Timeline

9.1
CRITICAL · CVSS v3.1 · 9b29abf9-4ab0-4765-b253-1875cd9b441e
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD16 Jun 2025 · 11:15 AM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
yes
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

4
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://metacpan.org/pod/perlfunc#rand
https://metacpan.org/release/GRYPHON/Mojolicious-Plugin-CaptchaPNG-1.04/diff/GRYPHON/Mojolicious-Plugin-CaptchaPNG-1.05/lib/Mojolicious/Plugin/CaptchaPNG.pm
https://metacpan.org/release/GRYPHON/Mojolicious-Plugin-CaptchaPNG-1.06/changes
https://security.metacpan.org/docs/guides/random-data-for-security.html
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