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Fencer Intel
high 7.7

CVE-2021-23420 json

Deserialization of Untrusted Data

published 5y ago modified last mo. also GHSA-4574-qv3w-fcmg , EUVD-2021-1967

cvss
7.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.7%
EPSS 2.7% chance of exploitation in 30 days, percentile 86%
public exploits
0
none known

Summary

This affects the package codeception/codeception from 4.0.0 and before 4.1.22, before 3.1.3. The RunProcess class can be leveraged as a gadget to run arbitrary commands on a system that is deserializing user input without validation.

Patch / fix

  • packagist codeception/codeception 3.1.3, 4.1.22
  • n/a codeception/codeception 3.1.3, 4.1.22

Is CVE-2021-23420 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Exploit prediction

2.71% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/JinYiTong/poc referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L/E:F/RL:O/RC:C
CNA 3.1 7.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 10.0 AV:N/AC:L/Au:N/C:C/I:C/A:C
GitHub 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
packagist codeception/codeception
<3.1.3
>=4.0.0, <4.1.22
3.1.3
4.1.22

Affected products

  • n/a codeception/codeception

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data

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.