In UsbCoreDxe, tampering with the contents of the USB working buffer using DMA while certain USB transactions are in process leads to a TOCTOU problem that could be used by an attacker to cause SMRAM corruption and escalation of privileges The UsbCoreDxe module creates a working buffer for USB transactions outside of SMRAM. The code which uses can be inside of SMM, making the working buffer untrusted input. The buffer can be corrupted by DMA transfers. The SMM code code attempts to sanitize pointers to ensure all pointers refer to the working buffer, but when a pointer is not found in the list of pointers to sanitize, the current action is not aborted, leading to undefined behavior. This issue was discovered by Insyde engineering based on the general description provided by Intel's iSTARE group. Fixed in: Kernel 5.0: Version 05.09. 21 Kernel 5.1: Version 05.17.21 Kernel 5.2: Version 05.27.21 Kernel 5.3: Version 05.36.21 Kernel 5.4: Version 05.44.21 Kernel 5.5: Version 05.52.21 https://www.insyde.com/security-pledge/SA-2022063

In UsbCoreDxe, tampering with the contents of the USB working buffer using DMA while certain USB transactions are in process leads to a TOCTOU problem that could be used by an attacker to cause SMRAM corruption and escalation of privileges The UsbCoreDxe module creates a working buffer for USB transactions outside of SMRAM. The code which uses can be inside of SMM, making the working buffer untrusted input. The buffer can be corrupted by DMA transfers. The SMM code code attempts to sanitize pointers to ensure all pointers refer to the working buffer, but when a pointer is not found in the list of pointers to sanitize, the current action is not aborted, leading to undefined behavior. This issue was discovered by Insyde engineering based on the general description provided by Intel's iSTARE group. Fixed in: Kernel 5.0: Version 05.09. 21 Kernel 5.1: Version 05.17.21 Kernel 5.2: Version 05.27.21 Kernel 5.3: Version 05.36.21 Kernel 5.4: Version 05.44.21 Kernel 5.5: Version 05.52.21 https://www.insyde.com/security-pledge/SA-2022063

An attacker with local access to the system could potentially disclose information from protected memory areas via a side-channel attack on the processor cache. Existing CommBuffer checks in SmmEntryPoint will not catch underflow when computing BufferSize. An issue was discovered in IhisiSmm in Insyde InsydeH2O with kernel 5.0 through 5.5. IHISI function 0x17 verifies that the output buffer lies within the command buffer but does not verify that output data does not go beyond the end of the command buffer. In particular, the GetFlashTable function is called directly on the Command Buffer before the DataSize is check, leading to possible circumstances where the data immediately following the command buffer could be destroyed before returning a buffer size error. Using SPI injection, it is possible to modify the FDM contents after it has been measured. This TOCTOU attack could be used to alter data and code used by the remainder of the boot process. Some versions of InsydeH2O use the FreeType tools to embed fonts into the BIOS. InsydeH2O does not use the FreeType API at runtime and usage during build time does not produce a vulnerability in the BIOS. The CVSS reflects this limited usage. In UsbCoreDxe, untrusted input may allow SMRAM or OS memory tampering Use of untrusted pointers could allow OS or SMRAM memory tampering leading to escalation of privileges. This issue was discovered by Insyde during security review. https://www.insyde.com/security-pledge/SA-2022058 In UsbCor…