{"id":"CVE-2021-33834","aliases":["EUVD-2021-20508","GHSA-2q86-2ww4-wc89"],"status":"published","title":"An issue was discovered in iscflashx64.sys 3.9.3.0 in Insyde H2OFFT 6.20.00. When handling IOCTL...","description":"An issue was discovered in iscflashx64.sys 3.9.3.0 in Insyde H2OFFT 6.20.00. When handling IOCTL 0x22229a, the input used to allocate a buffer and copy memory is mishandled. This could cause memory corruption or a system crash.","severity":{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.00189,"percentile":0.08585,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-787"],"published":"2023-09-08T00:00:00Z","modified":"2026-06-17T03:55:17Z","products":[{"vendor":"insyde","product":"h2offt"},{"vendor":"insyde","product":"iscflashx64.sys"}],"references":[{"url":"https://www.insyde.com/security-pledge","tags":["x_transferred","Not Applicable"]},{"url":"https://www.insyde.com/security-pledge/SA-2021004","tags":["x_transferred","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-33834"},{"url":"https://github.com/advisories/GHSA-2q86-2ww4-wc89"}],"sources":{"cve":[{"id":"CVE-2021-33834","description":"An issue was discovered in iscflashx64.sys 3.9.3.0 in Insyde H2OFFT 6.20.00. When handling IOCTL 0x22229a, the input used to allocate a buffer and copy memory is mishandled. This could cause memory corruption or a system crash.","status":"published","published":"2023-09-08T00:00:00Z","modified":"2024-09-26T18:43:44.319Z","updated_at":"2026-11-02T14:33:10.555814Z"}],"euvd":[{"id":"EUVD-2021-20508","description":"An issue was discovered in iscflashx64.sys 3.9.3.0 in Insyde H2OFFT 6.20.00. When handling IOCTL 0x22229a, the input used to allocate a buffer and copy memory is mishandled. This could cause memory corruption or a system crash.","status":"published","published":"2023-09-08T00:00:00Z","modified":"2024-09-26T18:43:44Z","updated_at":"2026-11-03T00:28:07.565611Z"}],"ghsa":[{"id":"GHSA-2q86-2ww4-wc89","title":"An issue was discovered in iscflashx64.sys 3.9.3.0 in Insyde H2OFFT 6.20.00. When handling IOCTL...","description":"An issue was discovered in iscflashx64.sys 3.9.3.0 in Insyde H2OFFT 6.20.00. When handling IOCTL 0x22229a, the input used to allocate a buffer and copy memory is mishandled. This could cause memory corruption or a system crash.","status":"published","published":"2023-09-08T03:30:20Z","modified":"2024-04-04T07:33:40Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","level":"high"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:56:52.639328Z"}],"nvd":[{"id":"CVE-2021-33834","description":"An issue was discovered in iscflashx64.sys 3.9.3.0 in Insyde H2OFFT 6.20.00. When handling IOCTL 0x22229a, the input used to allocate a buffer and copy memory is mishandled. This could cause memory corruption or a system crash.","status":"published","published":"2023-09-08T02:15:07.503Z","modified":"2026-06-17T03:55:17.26Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:07:07.764332Z"}]}}