What’s Vulnerable › Vulnerabilities

CVE-2020-5953

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2022-02-03 · updated 2026-08-11

Description

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 of SMRAM. This can result in code execution in SMM (escalating privilege from ring 0 to ring -2).

Affected products

• Insydeh2O: 5.12.09.0074, 5.23.04.0045, 5.23.45.0023, 5.33.15.0034, 5.34.03.0029, 5.42.03.0010
• Siemens Ruggedcom Ape1808 Firmware: all versions
• Siemens Simatic Field Pg M5 Firmware: all versions
• Siemens Simatic Field Pg M6 Firmware: all versions
• Siemens Simatic Ipc127E Firmware: all versions
• Siemens Simatic Ipc227G Firmware: all versions
• Siemens Simatic Ipc277G Firmware: all versions
• Siemens Simatic Ipc327G Firmware: all versions
• Siemens Simatic Ipc377G Firmware: all versions
• Siemens Simatic Ipc427E Firmware: all versions
• Siemens Simatic Ipc477E Firmware: all versions
• Siemens Simatic Ipc477E Pro Firmware: all versions
• Siemens Simatic Ipc627E Firmware: all versions
• Siemens Simatic Ipc647E Firmware: all versions
• Siemens Simatic Ipc677E Firmware: all versions
• Siemens Simatic Ipc847E Firmware: all versions
• Siemens Simatic Itp1000 Firmware: all versions

References

• https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf
• https://security.netapp.com/advisory/ntap-20220222-0005/
• https://www.insyde.com/products
• https://www.insyde.com/security-pledge
• https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf
• https://security.netapp.com/advisory/ntap-20220222-0005/
• https://www.insyde.com/products
• https://www.insyde.com/security-pledge
• https://www.kb.cert.org/vuls/id/796611
• https://cert-portal.siemens.com/productcert/html/ssa-306654.html

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