8.8

CVE-2021-21865: codesys development_system Deserialization of Untrusted Data

CVSS: 8.8v3.0HighModified
Published 02-08-2021Last modified 03-08-2024
Open JSON

Vulnerability summary

CVE-2021-21865 is a high (CVSS 8.8) Deserialization of Untrusted Data vulnerability in codesys development_system. EPSS estimates a 1.40% chance of exploitation in the next 30 days, higher than 72% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.8/10
010
High · v3.0 (CVE.org)
EPSS score
1.40%
0%100%
Low · +0.10 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 02-08-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

Description

A unsafe deserialization vulnerability exists in the PackageManagement.plugin ExtensionMethods.Clone() functionality of CODESYS GmbH CODESYS Development System 3.5.16. A specially crafted file can lead to arbitrary command execution. An attacker can provide a malicious file to trigger this vulnerability.

CVSS metrics

4 scores · 2 sources · 3 versions

EPSS trend

Probability

1.40%

Chance of exploitation in the next 30 days

Percentile

72%

Versus all other CVEs

30-day change

+0.10 pp

From 1.30% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.40%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Codesys1 product

1 vendor · 1 product

References

2 links