CVE-2021-33627: Buffer Overflow
An issue was discovered in Insyde InsydeH2O 5.x, affecting FwBlockServiceSmm. Software SMI services that use the Communicate() function of the EFISMMCOMMUNICATIONPROTOCOL do not check whether the address of the buffer is valid, which allows use of SMRAM, MMIO, or OS kernel addresses
Other sources
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 EFISMMCOMMUNICATIONPROTOCOL do not check whether the address of the buffer is valid, which allows use of SMRAM, MMIO, or OS kernel addresses.
— MITRE
Affected Software
Event History
Frequently Asked Questions
What is the vulnerability ID for this issue?
The vulnerability ID for this issue is CVE-2021-33627.
What is the severity level of CVE-2021-33627?
The severity level of CVE-2021-33627 is high with a CVSS score of 8.2.
What software is affected by CVE-2021-33627?
Insyde InsydeH2O 5.x and Siemens Simatic Field Pg M5 Firmware are affected by CVE-2021-33627.
How does CVE-2021-33627 impact the affected software?
CVE-2021-33627 allows an attacker to use SMRAM, MMIO, or OS kernel addresses through the Communicate() function of the EFI_SMM_COMMUNICATION_PROTOCOL.
Are there any available fixes for CVE-2021-33627?
For available fixes, please refer to the vendor's security advisory and security pledge.