CVE-2020-5953 json
A vulnerability exists in System Management Interrupt (SWSMI) handler of InsydeH2O UEFI Firmware code located in SWSMI handler that derefer…
published 4y ago modified 2mo ago also EUVD-2020-27107
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 21%
- public exploits
- 0
- none known
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 of SMRAM. This can result in code execution in SMM (escalating privilege from ring 0 to ring -2).
Patch / fix
- Siemens SIMATIC Field PG M5 V22.01.10
- Siemens SIMATIC Field PG M6 V26.01.13
- Siemens SIMATIC IPC127E V27.01.09
- Siemens SIMATIC IPC227G V28.01.04
- Siemens SIMATIC IPC277G V28.01.04
- Siemens SIMATIC IPC277G PRO V28.01.04
- Siemens SIMATIC IPC327G V28.01.04
- Siemens SIMATIC IPC377G V28.01.04
- Siemens SIMATIC IPC427E V21.01.17
- Siemens SIMATIC IPC477E V21.01.17
- Siemens SIMATIC IPC477E PRO V21.01.17
- Siemens SIMATIC IPC627E V25.02.12
- Siemens SIMATIC IPC647E V25.02.12
- Siemens SIMATIC IPC677E V25.02.12
- Siemens SIMATIC IPC847E V25.02.12
- Siemens SIMATIC ITP1000 V23.01.10
- Siemens SIPLUS IPC427E V21.01.17
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Check with FencerExploit prediction
0.28% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H |
| NVD | 2.0 | 6.9 | AV:L/AC:M/Au:N/C:C/I:C/A:C |
Affected products
- Siemens SIMATIC Field PG M5
- Siemens SIMATIC Field PG M6
- Siemens SIMATIC IPC127E
- Siemens SIMATIC IPC227G
- Siemens SIMATIC IPC277G
- Siemens SIMATIC IPC277G PRO
- Siemens SIMATIC IPC327G
- Siemens SIMATIC IPC377G
- Siemens SIMATIC IPC427E
- Siemens SIMATIC IPC477E
- Siemens SIMATIC IPC477E PRO
- Siemens SIMATIC IPC627E
- Siemens SIMATIC IPC647E
- Siemens SIMATIC IPC677E
- Siemens SIMATIC IPC847E
- Siemens SIMATIC ITP1000
- Siemens SIPLUS IPC427E
References
-
insyde.com
/products
product, vendor-advisory
-
insyde.com
/security-pledge
vendor-advisory
-
cert-portal.siemens.com
/productcert/pdf/ssa-306654.pdf
third-party-advisory
-
security.netapp.com
/advisory/ntap-20220222-0005/
third-party-advisory
- kb.cert.org /vuls/id/796611
- cert-portal.siemens.com /productcert/html/ssa-306654.html
Sources
- CVE List CVE-2020-5953
- NVD CVE-2020-5953
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