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Fencer Intel
low 2.6

CVE-2021-4240 json

phpservermon User.php generatePasswordResetToken predictable algorithm in random number generator

published 3y ago modified 4mo ago also GHSA-97w9-gcc7-vr8g , EUVD-2022-7294

cvss
2.6
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 59%
public exploits
0
none known

Summary

A vulnerability, which was classified as problematic, was found in phpservermon. This affects the function generatePasswordResetToken of the file src/psm/Service/User.php. The manipulation leads to use of predictable algorithm in random number generator. The exploit has been disclosed to the public and may be used. The name of the patch is 3daa804d5f56c55b3ae13bfac368bb84ec632193. It is recommended to apply a patch to fix this issue. The identifier VDB-213717 was assigned to this vulnerability.

Patch / fix

  • packagist phpservermon/phpservermon 3.6.0

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.89% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • huntr.dev https://huntr.dev/bounties/2-phpservermon/phpservermon/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 2.6 CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
packagist phpservermon/phpservermon
<3.6.0
3.6.0

Affected products

  • unspecified phpservermon

Classification

Weakness
  • CWE-331 Insufficient Entropy
  • CWE-330 Use of Insufficiently Random Values
  • CWE-1241 Use of Predictable Algorithm in Random Number Generator

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.