{"id":"CVE-2019-5636","aliases":["EUVD-2019-15211","GHSA-pv38-9q3c-3qq8"],"status":"published","title":"Beckhoff TwinCAT Discovery Service Denial of Service","description":"When a Beckhoff TwinCAT Runtime receives a malformed UDP packet, the ADS Discovery Service shuts down. Note that the TwinCAT devices are still performing as normal. This issue affects TwinCAT 2 version 2304 (and prior) and TwinCAT 3.1 version 4204.0 (and prior).","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":"2026-11-09","score":0.01427,"percentile":0.73158,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-404"],"published":"2019-11-21T19:16:12Z","modified":"2026-06-17T02:38:00Z","products":[{"vendor":"beckhoff","product":"twincat"},{"vendor":"beckhoff","product":"twincat 2"},{"vendor":"beckhoff","product":"twincat 3.1"}],"references":[{"url":"https://download.beckhoff.com/download/Document/product-security/Advisories/advisory-2019-004.pdf","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory"]},{"url":"https://blog.rapid7.com/2019/10/08/r7-2019-32-denial-of-service-vulnerabilities-in-beckhoff-twincat-plc-environment-fixed/","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2019-5636"},{"url":"https://github.com/advisories/GHSA-pv38-9q3c-3qq8"}],"sources":{"cve":[{"id":"CVE-2019-5636","title":"Beckhoff TwinCAT Discovery Service Denial of Service","description":"When a Beckhoff TwinCAT Runtime receives a malformed UDP packet, the ADS Discovery Service shuts down. Note that the TwinCAT devices are still performing as normal. This issue affects TwinCAT 2 version 2304 (and prior) and TwinCAT 3.1 version 4204.0 (and prior).","status":"published","published":"2019-11-21T19:16:12.913Z","modified":"2024-09-17T03:18:42.935Z","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-404"],"updated_at":"2026-11-02T14:20:18.411291Z"}],"euvd":[{"id":"EUVD-2019-15211","description":"When a Beckhoff TwinCAT Runtime receives a malformed UDP packet, the ADS Discovery Service shuts down. Note that the TwinCAT devices are still performing as normal. This issue affects TwinCAT 2 version 2304 (and prior) and TwinCAT 3.1 version 4204.0 (and prior).","status":"published","published":"2019-11-21T19:16:12Z","modified":"2024-09-17T03:18:42Z","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":"2026-11-03T00:28:32.883624Z"}],"ghsa":[{"id":"GHSA-pv38-9q3c-3qq8","title":"When a Beckhoff TwinCAT Runtime receives a malformed UDP packet, the ADS Discovery Service shuts...","description":"When a Beckhoff TwinCAT Runtime receives a malformed UDP packet, the ADS Discovery Service shuts down. Note that the TwinCAT devices are still performing as normal.","status":"published","published":"2022-05-24T17:01:46Z","modified":"2023-01-28T05:08:21Z","updated_at":"2026-11-02T14:44:36.910779Z"}],"nvd":[{"id":"CVE-2019-5636","description":"When a Beckhoff TwinCAT Runtime receives a malformed UDP packet, the ADS Discovery Service shuts down. Note that the TwinCAT devices are still performing as normal. This issue affects TwinCAT 2 version 2304 (and prior) and TwinCAT 3.1 version 4204.0 (and prior).","status":"published","published":"2019-11-21T20:15:15.897Z","modified":"2026-06-17T02:38:00.363Z","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":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","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-404"],"updated_at":"2026-11-02T14:05:37.024431Z"}]}}