{"id":"CVE-2021-21958","aliases":["EUVD-2021-9129","GHSA-5fcw-h565-mjpq"],"status":"published","title":"A heap-based buffer overflow vulnerability exists in the Hword HwordApp.dll functionality of...","description":"A heap-based buffer overflow vulnerability exists in the Hword HwordApp.dll functionality of Hancom Office 2020 11.0.0.2353. A specially-crafted malformed file can lead to memory corruption and potential arbitrary code execution. An attacker can provide a malicious file to trigger this vulnerability.","severity":{"version":"3.0","score":7.8,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.011,"percentile":0.66099,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-122","CWE-787"],"published":"2022-02-16T16:38:31Z","modified":"2026-06-17T03:36:25Z","products":[{"vendor":"hancom","product":"hancom_office_2020"}],"references":[{"url":"https://talosintelligence.com/vulnerability_reports/TALOS-2021-1386","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21958"},{"url":"https://blog.talosintelligence.com/2022/02/vuln-spotlight-.html","tags":["Exploit","Third Party Advisory"]},{"url":"https://github.com/advisories/GHSA-5fcw-h565-mjpq"}],"sources":{"cve":[{"id":"CVE-2021-21958","description":"A heap-based buffer overflow vulnerability exists in the Hword HwordApp.dll functionality of Hancom Office 2020 11.0.0.2353. A specially-crafted malformed file can lead to memory corruption and potential arbitrary code execution. An attacker can provide a malicious file to trigger this vulnerability.","status":"published","published":"2022-02-16T16:38:31Z","modified":"2025-04-15T19:10:05.119Z","cvss":[{"version":"3.0","score":7.8,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-122"],"updated_at":"2026-11-02T14:33:00.137099Z"}],"euvd":[{"id":"EUVD-2021-9129","description":"A heap-based buffer overflow vulnerability exists in the Hword HwordApp.dll functionality of Hancom Office 2020 11.0.0.2353. A specially-crafted malformed file can lead to memory corruption and potential arbitrary code execution. An attacker can provide a malicious file to trigger this vulnerability.","status":"published","published":"2022-02-16T16:38:31Z","modified":"2025-04-15T19:10:05Z","cvss":[{"version":"3.0","score":7.8,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T20:52:26.772603Z"}],"ghsa":[{"id":"GHSA-5fcw-h565-mjpq","title":"A heap-based buffer overflow vulnerability exists in the Hword HwordApp.dll functionality of...","description":"A heap-based buffer overflow vulnerability exists in the Hword HwordApp.dll functionality of Hancom Office 2020 11.0.0.2353. A specially-crafted malformed file can lead to memory corruption and potential arbitrary code execution. An attacker can provide a malicious file to trigger this vulnerability.","status":"published","published":"2022-02-17T00:00:33Z","modified":"2023-02-03T05:06:18Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:53:52.731364Z"}],"nvd":[{"id":"CVE-2021-21958","description":"A heap-based buffer overflow vulnerability exists in the Hword HwordApp.dll functionality of Hancom Office 2020 11.0.0.2353. A specially-crafted malformed file can lead to memory corruption and potential arbitrary code execution. An attacker can provide a malicious file to trigger this vulnerability.","status":"published","published":"2022-02-16T17:15:10.297Z","modified":"2026-06-17T03:36:25.913Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"3.0","score":7.8,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"},{"version":"2.0","score":6.8,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-122","CWE-787"],"updated_at":"2026-11-02T14:07:04.6896Z"}]}}