CVE-2021-33485: Codesys Control

Critical severity, CVSS 9.8. EPSS: 1.1% chance of exploitation in the next 30 days.

CODESYS Control Runtime system before 3.5.17.10 has a Heap-based Buffer Overflow.

Affected products

• Codesys Control: before 4.2.0.0 (fixed in 4.2.0.0); up to and including 4.2.0.0
• Codesys Control Rte: before 3.5.17.10 (fixed in 3.5.17.10)
• Codesys Control Runtime System Toolkit: before 3.5.17.10 (fixed in 3.5.17.10)
• Codesys Control Win Sl: before 3.5.17.10 (fixed in 3.5.17.10)
• Codesys Embedded Target Visu Toolkit: before 3.5.17.10 (fixed in 3.5.17.10)
• Codesys HMI: before 3.5.17.10 (fixed in 3.5.17.10)
• Codesys Remote Target Visu Toolkit: before 3.5.17.10 (fixed in 3.5.17.10)

Published 2021-08-03. Last modified 2026-06-17.