CVE-2021-40142: Opcfoundation Local Discover Server

High severity, CVSS 7.5. EPSS: 2.6% chance of exploitation in the next 30 days.

In OPC Foundation Local Discovery Server (LDS) before 1.04.402.463, remote attackers can cause a denial of service (DoS) by sending carefully crafted messages that lead to Access of a Memory Location After the End of a Buffer.

Affected products

• Opcfoundation Local Discover Server: before 1.04.402.463 (fixed in 1.04.402.463)
• Siemens SIMATIC Net Pc: version 14 only; version 15 only; version 16 only; version 17 only
• Siemens SIMATIC Process Historian Opc Ua Server Firmware: before 2022 (fixed in 2022); version 2022 only
• Siemens SIMATIC Wincc: affected versions not specified
• Siemens SIMATIC Wincc Runtime: affected versions not specified
• Siemens SIMATIC Wincc Unified Scada Runtime: affected versions not specified
• Siemens Telecontrol Server Basic: version 3.0 only

Published 2021-08-27. Last modified 2026-06-17.