CVE-2021-33626 json
A vulnerability exists in SMM (System Management Mode) branch that registers a SWSMI handler that does not sufficiently check or validate t…
published 2021-10-01 5 y ago modified 2026-08-11 2 mo ago also EUVD-2021-20303
- cvss
- 7.8
- 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 23%
- public exploits
- 0
- none known
Summary
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(QWORD values for CommBuffer). This can be used by an attacker to corrupt data in SMRAM memory and even lead to arbitrary code execution.
Patch / fix
- Siemens RUGGEDCOM APE1808 - BIOS V1.0.202N
- 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
Exploit prediction
0.31% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 4.6 | AV:L/AC:L/Au:N/C:P/I:P/A:P |
Affected products
- Siemens RUGGEDCOM APE1808 - BIOS
- 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
Classification
- Weakness
-
- CWE-829 Inclusion of Functionality from Untrusted Control Sphere
References
-
insyde.com
/security-pledge
vendor-advisory
-
insyde.com
/security-pledge/SA-2021001
vendor-advisory
-
security.netapp.com
/advisory/ntap-20220216-0006/
third-party-advisory
-
cert-portal.siemens.com
/productcert/pdf/ssa-306654.pdf
third-party-advisory
- kb.cert.org /vuls/id/796611
- cert-portal.siemens.com /productcert/html/ssa-306654.html
Sources
- CVE List CVE-2021-33626
- NVD CVE-2021-33626
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