CVE-2021-33627

moderate-risk
Published 2022-02-03

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.

Do I need to act?

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0.09% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
8
CVSS 8.2/10 High
LOCAL / LOW complexity

Affected Products (15)

Simatic Field Pg M6 Firmware
Simatic Ipc127E Firmware
Simatic Ipc227G Firmware
Simatic Ipc277G Firmware
Simatic Ipc327G Firmware
Simatic Ipc377G Firmware
Simatic Ipc627E Firmware
Simatic Ipc647E Firmware
Simatic Ipc677E Firmware
Simatic Ipc847E Firmware

Affected Vendors

Siemens Insyde

References (9)

Third Party Advisory https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf
Third Party Advisory https://security.netapp.com/advisory/ntap-20220222-0002/
Vendor Advisory https://www.insyde.com/security-pledge
Vendor Advisory https://www.insyde.com/security-pledge/SA-2022022
Third Party Advisory https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf
Third Party Advisory https://security.netapp.com/advisory/ntap-20220222-0002/
Vendor Advisory https://www.insyde.com/security-pledge
Vendor Advisory https://www.insyde.com/security-pledge/SA-2022022
https://www.kb.cert.org/vuls/id/796611
43
/ 100
moderate-risk
Severity 25/34 · High
Exploitability 0/34 · Minimal
Exposure 18/34 · Moderate