{"id":"CVE-2021-21971","aliases":["EUVD-2021-9142","GHSA-3975-hvrj-7hm8"],"status":"published","title":"An out-of-bounds write vulnerability exists in the URL_decode functionality of Sealevel Systems,...","description":"An out-of-bounds write vulnerability exists in the URL_decode functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. A specially-crafted MQTT payload can lead to an out-of-bounds write. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.","severity":{"version":"3.0","score":3.7,"vector":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00696,"percentile":0.53356,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-787"],"published":"2022-02-04T22:29:02Z","modified":"2026-06-17T03:36:28Z","products":[{"vendor":"sealevel","product":"seaconnect_370w_firmware"}],"references":[{"url":"https://talosintelligence.com/vulnerability_reports/TALOS-2021-1406","tags":["x_refsource_MISC","x_transferred","Not Applicable","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21971"},{"url":"https://talosintelligence.com/vulnerability_reports/TALOS-2021-1397","tags":["Exploit","Technical Description","Third Party Advisory"]},{"url":"https://github.com/advisories/GHSA-3975-hvrj-7hm8"}],"sources":{"cve":[{"id":"CVE-2021-21971","description":"An out-of-bounds write vulnerability exists in the URL_decode functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. A specially-crafted MQTT payload can lead to an out-of-bounds write. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.","status":"published","published":"2022-02-04T22:29:02Z","modified":"2025-04-15T19:11:19.375Z","cvss":[{"version":"3.0","score":3.7,"vector":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"low","assessor":"cna"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:33:00.137099Z"}],"euvd":[{"id":"EUVD-2021-9142","description":"An out-of-bounds write vulnerability exists in the URL_decode functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. A specially-crafted MQTT payload can lead to an out-of-bounds write. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.","status":"published","published":"2022-02-04T22:29:02Z","modified":"2025-04-15T19:11:19Z","cvss":[{"version":"3.0","score":3.7,"vector":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"low"}],"updated_at":"2026-11-02T20:52:26.772603Z"}],"ghsa":[{"id":"GHSA-3975-hvrj-7hm8","title":"An out-of-bounds write vulnerability exists in the URL_decode functionality of Sealevel Systems,...","description":"An out-of-bounds write vulnerability exists in the URL_decode functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. A specially-crafted MQTT payload can lead to an out-of-bounds write. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.","status":"published","published":"2022-02-10T00:00:43Z","modified":"2023-02-03T05:05:22Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"medium"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:53:43.901857Z"}],"nvd":[{"id":"CVE-2021-21971","description":"An out-of-bounds write vulnerability exists in the URL_decode functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. A specially-crafted MQTT payload can lead to an out-of-bounds write. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.","status":"published","published":"2022-02-04T23:15:10.83Z","modified":"2026-06-17T03:36:28.5Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"primary"},{"version":"3.0","score":3.7,"vector":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"low","assessor":"secondary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:07:04.178977Z"}]}}