{"id":"CVE-2021-33627","aliases":["EUVD-2021-20304","GHSA-g6pg-5762-5mq6"],"status":"published","title":"A vulnerability exists in SMM (System Management Mode) branch that registers a SWSMI handler that...","description":"An issue was discovered in Insyde InsydeH2O Kernel 5.0 before 05.09.11, 5.1 before 05.17.11, 5.2 before 05.27.11, 5.3 before 05.36.11, 5.4 before 05.44.11, and 5.5 before 05.52.11 affecting FwBlockServiceSmm. Software SMI services that use the Communicate() function of the EFI_SMM_COMMUNICATION_PROTOCOL do not check whether the address of the buffer is valid, which allows use of SMRAM, MMIO, or OS kernel addresses.","severity":{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.00328,"percentile":0.26232,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-119"],"published":"2022-02-03T01:30:36Z","modified":"2026-08-11T15:31:36Z","products":[{"vendor":"insyde","product":"insydeh2o"},{"vendor":"siemens","product":"ruggedcom ape1808 - bios"},{"vendor":"siemens","product":"simatic field pg m5"},{"vendor":"siemens","product":"simatic field pg m6"},{"vendor":"siemens","product":"simatic ipc127e"},{"vendor":"siemens","product":"simatic ipc227g"},{"vendor":"siemens","product":"simatic ipc277g"},{"vendor":"siemens","product":"simatic ipc327g"},{"vendor":"siemens","product":"simatic ipc377g"},{"vendor":"siemens","product":"simatic ipc427e"},{"vendor":"siemens","product":"simatic ipc477e"},{"vendor":"siemens","product":"simatic ipc477e pro"},{"vendor":"siemens","product":"simatic ipc627e"},{"vendor":"siemens","product":"simatic ipc647e"},{"vendor":"siemens","product":"simatic ipc677e"},{"vendor":"siemens","product":"simatic ipc847e"},{"vendor":"siemens","product":"simatic itp1000"},{"vendor":"siemens","product":"simatic_field_pg_m5_firmware"},{"vendor":"siemens","product":"simatic_field_pg_m6_firmware"},{"vendor":"siemens","product":"simatic_ipc127e_firmware"},{"vendor":"siemens","product":"simatic_ipc227g_firmware"},{"vendor":"siemens","product":"simatic_ipc277g_firmware"},{"vendor":"siemens","product":"simatic_ipc327g_firmware"},{"vendor":"siemens","product":"simatic_ipc377g_firmware"},{"vendor":"siemens","product":"simatic_ipc427e_firmware"},{"vendor":"siemens","product":"simatic_ipc477e_firmware"},{"vendor":"siemens","product":"simatic_ipc627e_firmware"},{"vendor":"siemens","product":"simatic_ipc647e_firmware"},{"vendor":"siemens","product":"simatic_ipc677e_firmware"},{"vendor":"siemens","product":"simatic_ipc847e_firmware"},{"vendor":"siemens","product":"simatic_itp1000_firmware"},{"vendor":"siemens","product":"simatic ipc277g pro"},{"vendor":"siemens","product":"siplus ipc427e"}],"references":[{"url":"https://www.insyde.com/security-pledge","tags":["x_transferred","Vendor Advisory"]},{"url":"https://www.insyde.com/security-pledge/SA-2022022","tags":["x_transferred","Vendor Advisory"]},{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf","tags":["x_transferred","Third Party Advisory"]},{"url":"https://security.netapp.com/advisory/ntap-20220222-0002/","tags":["x_transferred","Third Party Advisory"]},{"url":"https://www.kb.cert.org/vuls/id/796611"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-306654.html"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-33627"},{"url":"https://security.netapp.com/advisory/ntap-20220222-0002"},{"url":"https://github.com/advisories/GHSA-g6pg-5762-5mq6"}],"sources":{"cve":[{"id":"CVE-2021-33627","description":"An issue was discovered in Insyde InsydeH2O Kernel 5.0 before 05.09.11, 5.1 before 05.17.11, 5.2 before 05.27.11, 5.3 before 05.36.11, 5.4 before 05.44.11, and 5.5 before 05.52.11 affecting FwBlockServiceSmm. Software SMI services that use the Communicate() function of the EFI_SMM_COMMUNICATION_PROTOCOL do not check whether the address of the buffer is valid, which allows use of SMRAM, MMIO, or OS kernel addresses.","status":"published","published":"2022-02-03T01:30:36Z","modified":"2026-08-11T12:22:07.04Z","updated_at":"2026-11-02T14:33:10.204494Z"}],"euvd":[{"id":"EUVD-2021-20304","description":"An issue was discovered in Insyde InsydeH2O Kernel 5.0 before 05.09.11, 5.1 before 05.17.11, 5.2 before 05.27.11, 5.3 before 05.36.11, 5.4 before 05.44.11, and 5.5 before 05.52.11 affecting FwBlockServiceSmm. Software SMI services that use the Communicate() function of the EFI_SMM_COMMUNICATION_PROTOCOL do not check whether the address of the buffer is valid, which allows use of SMRAM, MMIO, or OS kernel addresses.","status":"published","published":"2022-02-03T01:30:36Z","modified":"2026-08-11T12:22:07Z","updated_at":"2026-11-02T18:02:00.294626Z"}],"ghsa":[{"id":"GHSA-g6pg-5762-5mq6","title":"A vulnerability exists in SMM (System Management Mode) branch that registers a SWSMI handler that...","description":"A vulnerability exists in SMM (System Management Mode) branch that registers a SWSMI handler that does not sufficiently check or validate the allocated buffer pointer(CommBuffer). This can be used by an attacker to corrupt data in SMRAM memory and even lead to arbitrary code execution.","status":"published","published":"2022-02-10T00:01:00Z","modified":"2026-08-11T15:31:36Z","cvss":[{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-119"],"updated_at":"2026-11-02T15:10:17.573081Z"}],"nvd":[{"id":"CVE-2021-33627","description":"An issue was discovered in Insyde InsydeH2O Kernel 5.0 before 05.09.11, 5.1 before 05.17.11, 5.2 before 05.27.11, 5.3 before 05.36.11, 5.4 before 05.44.11, and 5.5 before 05.52.11 affecting FwBlockServiceSmm. Software SMI services that use the Communicate() function of the EFI_SMM_COMMUNICATION_PROTOCOL do not check whether the address of the buffer is valid, which allows use of SMRAM, MMIO, or OS kernel addresses.","status":"published","published":"2022-02-03T02:15:06.983Z","modified":"2026-08-11T13:17:19.79Z","cvss":[{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":7.2,"vector":"AV:L/AC:L/Au:N/C:C/I:C/A:C","level":"high","assessor":"primary"}],"cwes":["CWE-119"],"updated_at":"2026-11-02T14:07:04.178977Z"}]}}