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Fencer Vulns
high 7.8

CVE-2021-29240 json

The Package Manager of CODESYS Development System 3 before 3.5.17.0 does not check the validity of packages before installation and may be…

published 2021-05-04 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-15879

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 61%
public exploits
0
none known

Summary

The Package Manager of CODESYS Development System 3 before 3.5.17.0 does not check the validity of packages before installation and may be used to install CODESYS packages with malicious content.

Patch / fix

  • codesys development_system 3.5.17.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-26-076-01 updated cvss 7.8

CODESYS in Festo Automation Suite

  • CODESYS Development System 3.0 Festo Automation Suite 2.8.0.137, Festo Automation Suite < 2.8.0.138 CODESYS Development System 3.5.16.10 Festo Automation Suite 2.8.0.137, Festo Automation Suite < 2.8.0.138
    affected: mitigation
  • Festo Automation Suite 2.8.0.138 CODESYS Development System 3.5.21.20
    fixed

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

Exploit prediction

0.94% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • customers.codesys.com https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=14636&token=1ce7e6e4cbe4651989ede418450d7c82e972bdf2&download= referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

References

Sources

Fencer Vulns 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.