{"id":"CVE-2020-5953","title":"A vulnerability exists in System Management Interrupt (SWSMI) handler of InsydeH2O UEFI Firmware code located in SWSMI handler that dereferences gRT (EFI_RUNTIME_SERVICES) pointer to call a GetVariable service, which is located outside o…","summary":"A vulnerability exists in System Management Interrupt (SWSMI) handler of InsydeH2O UEFI Firmware code located in SWSMI handler that dereferences gRT (EFI_RUNTIME_SERVICES) pointer to call a GetVariable service, which is located outside o…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","vendor":"insyde","product":"insydeh2o","affected":["insydeh2o = 5.12.09.0074","insydeh2o = 5.23.04.0045","insydeh2o = 5.23.45.0023","insydeh2o = 5.33.15.0034","insydeh2o = 5.34.03.0029","insydeh2o = 5.42.03.0010","ruggedcom_ape1808_firmware","simatic_field_pg_m6_firmware","simatic_ipc127e_firmware","simatic_ipc227g_firmware","simatic_ipc277g_firmware","simatic_itp1000_firmware","simatic_ipc477e_pro_firmware","simatic_ipc627e_firmware","simatic_ipc647e_firmware","simatic_ipc677e_firmware","simatic_ipc847e_firmware","simatic_ipc327g_firmware","simatic_ipc377g_firmware","simatic_ipc427e_firmware","simatic_ipc477e_firmware","simatic_field_pg_m5_firmware"],"published":"2022-02-03","updated":"2026-08-11","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2020-5953","references":[{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf","label":"cve@mitre.org"},{"url":"https://security.netapp.com/advisory/ntap-20220222-0005/","label":"cve@mitre.org"},{"url":"https://www.insyde.com/products","label":"cve@mitre.org"},{"url":"https://www.insyde.com/security-pledge","label":"cve@mitre.org"},{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.netapp.com/advisory/ntap-20220222-0005/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.insyde.com/products","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.insyde.com/security-pledge","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.kb.cert.org/vuls/id/796611","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-306654.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd"],"epss":0.00284,"epssPercentile":0.21102,"ingestedAt":"2026-08-11T16:47:01.700Z","slug":"CVE-2020-5953","body":"## Overview\n\nA vulnerability exists in System Management Interrupt (SWSMI) handler of InsydeH2O UEFI Firmware code located in SWSMI handler that dereferences gRT (EFI_RUNTIME_SERVICES) pointer to call a GetVariable service, which is located outside of SMRAM. This can result in code execution in SMM (escalating privilege from ring 0 to ring -2).\n\n## Affected\n\n- `insydeh2o = 5.12.09.0074`\n- `insydeh2o = 5.23.04.0045`\n- `insydeh2o = 5.23.45.0023`\n- `insydeh2o = 5.33.15.0034`\n- `insydeh2o = 5.34.03.0029`\n- `insydeh2o = 5.42.03.0010`\n- `ruggedcom_ape1808_firmware`\n- `simatic_field_pg_m6_firmware`\n- `simatic_ipc127e_firmware`\n- `simatic_ipc227g_firmware`\n- `simatic_ipc277g_firmware`\n- `simatic_itp1000_firmware`\n- `simatic_ipc477e_pro_firmware`\n- `simatic_ipc627e_firmware`\n- `simatic_ipc647e_firmware`\n- `simatic_ipc677e_firmware`\n- `simatic_ipc847e_firmware`\n- `simatic_ipc327g_firmware`\n- `simatic_ipc377g_firmware`\n- `simatic_ipc427e_firmware`\n- `simatic_ipc477e_firmware`\n- `simatic_field_pg_m5_firmware`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}