{"id":"CVE-2020-12526","aliases":["EUVD-2020-4828","GHSA-53xf-f462-gx5v"],"status":"published","title":"BECKHOFF: DoS-Vulnerability for TwinCAT OPC UA Server and IPC Diagnostics UA Server","description":"TwinCAT OPC UA Server in versions up to 2.3.0.12 and IPC Diagnostics UA Server in versions up to 3.1.0.1 from Beckhoff Automation GmbH \u0026 Co. KG are vulnerable to denial of service attacks. The attacker needs to send several specifically crafted requests to the running OPC UA server. After some of these requests the OPC UA server is no longer responsive to any client. This is without effect to the real-time functionality of IPCs.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00955,"percentile":0.61831,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-20"],"published":"2021-05-13T13:45:24Z","modified":"2026-06-17T02:51:58Z","products":[{"vendor":"beckhoff","product":"ipc diagnostics ua server"},{"vendor":"beckhoff","product":"ipc_diagnostics_ua_server"},{"vendor":"beckhoff","product":"tf6100"},{"vendor":"beckhoff","product":"twincat opc ua server"},{"vendor":"beckhoff","product":"twincat_opc_ua_server"},{"vendor":"beckhoff automation","product":"twincat opc ua server"}],"references":[{"url":"https://cert.vde.com/en-us/advisories/vde-2020-051","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory"]},{"url":"https://download.beckhoff.com/download/Document/product-security/Advisories/advisory-2021-001.pdf","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-12526"},{"url":"https://github.com/advisories/GHSA-53xf-f462-gx5v"}],"sources":{"cve":[{"id":"CVE-2020-12526","title":"BECKHOFF: DoS-Vulnerability for TwinCAT OPC UA Server and IPC Diagnostics UA Server","description":"TwinCAT OPC UA Server in versions up to 2.3.0.12 and IPC Diagnostics UA Server in versions up to 3.1.0.1 from Beckhoff Automation GmbH \u0026 Co. KG are vulnerable to denial of service attacks. The attacker needs to send several specifically crafted requests to the running OPC UA server. After some of these requests the OPC UA server is no longer responsive to any client. This is without effect to the real-time functionality of IPCs.","status":"published","published":"2021-05-13T13:45:24.098Z","modified":"2024-09-16T18:29:21.532Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:35:52.925152Z"}],"euvd":[{"id":"EUVD-2020-4828","description":"TwinCAT OPC UA Server in versions up to 2.3.0.12 and IPC Diagnostics UA Server in versions up to 3.1.0.1 from Beckhoff Automation GmbH \u0026 Co. KG are vulnerable to denial of service attacks. The attacker needs to send several specifically crafted requests to the running OPC UA server. After some of these requests the OPC UA server is no longer responsive to any client. This is without effect to the real-time functionality of IPCs.","status":"published","published":"2021-05-13T13:45:24Z","modified":"2024-09-16T18:29:21Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"updated_at":"2026-11-03T00:55:32.095421Z"}],"ghsa":[{"id":"GHSA-53xf-f462-gx5v","title":"TwinCAT OPC UA Server in versions up to 2.3.0.12 and IPC Diagnostics UA Server in versions up to...","description":"TwinCAT OPC UA Server in versions up to 2.3.0.12 and IPC Diagnostics UA Server in versions up to 3.1.0.1 from Beckhoff Automation GmbH \u0026 Co. KG are vulnerable to denial of service attacks. The attacker needs to send several specifically crafted requests to the running OPC UA server. After some of these requests the OPC UA server is no longer responsive to any client. This is without effect to the real-time functionality of IPCs.","status":"published","published":"2022-05-24T19:02:23Z","modified":"2023-01-29T05:06:41Z","cwes":["CWE-20"],"updated_at":"2026-11-02T14:46:04.961867Z"}],"nvd":[{"id":"CVE-2020-12526","description":"TwinCAT OPC UA Server in versions up to 2.3.0.12 and IPC Diagnostics UA Server in versions up to 3.1.0.1 from Beckhoff Automation GmbH \u0026 Co. KG are vulnerable to denial of service attacks. The attacker needs to send several specifically crafted requests to the running OPC UA server. After some of these requests the OPC UA server is no longer responsive to any client. This is without effect to the real-time functionality of IPCs.","status":"published","published":"2021-05-13T14:15:17.457Z","modified":"2026-06-17T02:51:58.547Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:06:39.25999Z"}]}}