{"id":"CVE-2021-37740","aliases":["EUVD-2021-24221","GHSA-fgcc-2fx7-p23v"],"status":"published","title":"A denial of service vulnerability exists in MDT's firmware for the KNXnet/IP Secure router SCN...","description":"A denial of service vulnerability exists in MDT's firmware for the KNXnet/IP Secure router SCN-IP100.03 and KNX IP interface SCN-IP000.03 before v3.0.4, that allows a remote attacker to turn the device unresponsive to all requests on the KNXnet/IP Secure layer, until the device is rebooted, via a SESSION_REQUEST frame with a modified total length field.","severity":{"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","from":"nvd"},"epss":{"day":"2026-11-10","score":0.04618,"percentile":0.91766,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":false},"published":"2022-04-20T19:31:19Z","modified":"2026-06-17T04:01:05Z","exploits":[{"source":"pocgithub","id":"robertguetzkow/CVE-2021-37740","title":"robertguetzkow/CVE-2021-37740","date":"2022-04-01","url":"https://github.com/robertguetzkow/CVE-2021-37740"}],"products":[{"vendor":"mdt","product":"scn-ip000.03_firmware"},{"vendor":"mdt","product":"scn-ip100.03_firmware"}],"references":[{"url":"https://www.mdt.de/EN_IP_Interface_Router.html","tags":["x_refsource_MISC","x_transferred","Broken Link"]},{"url":"https://www.mdt.de/download/MDT_CL_SCN_IP_03_IP_Interface_Router.pdf","tags":["x_refsource_MISC","x_transferred","Release Notes","Vendor Advisory"]},{"url":"https://github.com/robertguetzkow/CVE-2021-37740","tags":["x_refsource_MISC","x_transferred","Exploit","Release Notes","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-37740"},{"url":"https://github.com/advisories/GHSA-fgcc-2fx7-p23v"}],"sources":{"cve":[{"id":"CVE-2021-37740","description":"A denial of service vulnerability exists in MDT's firmware for the KNXnet/IP Secure router SCN-IP100.03 and KNX IP interface SCN-IP000.03 before v3.0.4, that allows a remote attacker to turn the device unresponsive to all requests on the KNXnet/IP Secure layer, until the device is rebooted, via a SESSION_REQUEST frame with a modified total length field.","status":"published","published":"2022-04-20T19:31:19Z","modified":"2024-08-04T01:30:07.493Z","updated_at":"2026-11-02T14:32:58.359368Z"}],"euvd":[{"id":"EUVD-2021-24221","description":"A denial of service vulnerability exists in MDT's firmware for the KNXnet/IP Secure router SCN-IP100.03 and KNX IP interface SCN-IP000.03 before v3.0.4, that allows a remote attacker to turn the device unresponsive to all requests on the KNXnet/IP Secure layer, until the device is rebooted, via a SESSION_REQUEST frame with a modified total length field.","status":"published","published":"2022-04-20T19:31:19Z","modified":"2024-08-04T01:30:07Z","updated_at":"2026-11-03T03:24:26.118239Z"}],"ghsa":[{"id":"GHSA-fgcc-2fx7-p23v","title":"A denial of service vulnerability exists in MDT's firmware for the KNXnet/IP Secure router SCN...","description":"A denial of service vulnerability exists in MDT's firmware for the KNXnet/IP Secure router SCN-IP100.03 and KNX IP interface SCN-IP000.03 before v3.0.4, that allows a remote attacker to turn the device unresponsive to all requests on the KNXnet/IP Secure layer, until the device is rebooted, via a SESSION_REQUEST frame with a modified total length field.","status":"published","published":"2022-04-21T00:00:22Z","modified":"2023-01-27T05:01:51Z","cvss":[{"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"}],"updated_at":"2026-11-02T14:41:58.86931Z"}],"nvd":[{"id":"CVE-2021-37740","description":"A denial of service vulnerability exists in MDT's firmware for the KNXnet/IP Secure router SCN-IP100.03 and KNX IP interface SCN-IP000.03 before v3.0.4, that allows a remote attacker to turn the device unresponsive to all requests on the KNXnet/IP Secure layer, until the device is rebooted, via a SESSION_REQUEST frame with a modified total length field.","status":"published","published":"2022-04-20T20:15:07.993Z","modified":"2026-06-17T04:01:05.323Z","cvss":[{"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":7.8,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:C","level":"high","assessor":"primary"}],"updated_at":"2026-11-02T14:07:06.029737Z"}]}}