CVE-2021-34599: Improper Certificate Validation in CODESYS Git

Severity: high (CVSS 7.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-12-01 · updated 2026-06-17
Weakness: CWE-295

Description

Affected versions of CODESYS Git in Versions prior to V1.1.0.0 lack certificate validation in HTTPS handshakes. CODESYS Git does not implement certificate validation by default, so it does not verify that the server provides a valid and trusted HTTPS certificate. Since the certificate of the server to which the connection is made is not properly verified, the server connection is vulnerable to a man-in-the-middle attack.

Affected products

CODESYS Git: before 1.1.0.0 — fixed in 1.1.0.0

How to fix

Upgrade to a fixed version: CODESYS Git 1.1.0.0. Check the vendor advisory for mitigations.

References

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