A flaw was found in edk2. A integer underflow in the SmmEntryPoint function leads to a write into the SMM region allowing a local attacker with administration privileges on the system to execute code within the SMM privileged context. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Initialization function in PnpSmm could lead to SMRAM corruption when using subsequent PNP SMI functions Initialization function in PnpSmm could lead to SMRAM corruption when using subsequent PNP SMI functions. This issue was discovered by Insyde engineering during a security review. Fixed in: Kernel 5.1: Version 05.17.25 Kernel 5.2: Version 05.27.25 Kernel 5.3: Version 05.36.25 Kernel 5.4: Version 05.44.25 Kernel 5.5: Version 05.52.25 https://www.insyde.com/security-pledge/SA-2022064

Incorrect pointer checks within the NvmExpressDxe driver can allow tampering with SMRAM and OS memory Incorrect pointer checks within the NvmExpressDxe driver can allow tampering with SMRAM and OS memory. This issue was discovered by Insyde during security review. Fixed in: Kernel 5.1: Version 05.17.23 Kernel 5.2: Version 05.27.23 Kernel 5.3: Version 05.36.23 Kernel 5.4: Version 05.44.23 Kernel 5.5: Version 05.52.23 https://www.insyde.com/security-pledge/SA-2022061

Manipulation of the input address in PnpSmm function 0x52 could be used by malware to overwrite SMRAM or OS kernel memory. Function 0x52 of the PnpSmm driver is passed the address and size of data to write into the SMBIOS table, but manipulation of the address could be used by malware to overwrite SMRAM or OS kernel memory. This issue was discovered by Insyde engineering during a security review. This issue is fixed in: Kernel 5.0: 05.09.41 Kernel 5.1: 05.17.43 Kernel 5.2: 05.27.30 Kernel 5.3: 05.36.30 Kernel 5.4: 05.44.30 Kernel 5.5: 05.52.30 https://www.insyde.com/security-pledge/SA-2022065

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. It was 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-2022058

SMI functions in AhciBusDxe use untrusted inputs leading to corruption of SMRAM. SMI functions in AhciBusDxe use untrusted inputs leading to corruption of SMRAM. This issue was discovered by Insyde during security review. It was fixed in: Kernel 5.0: version 05.09.18 Kernel 5.1: version 05.17.18 Kernel 5.2: version 05.27.18 Kernel 5.3: version 05.36.18 Kernel 5.4: version 05.44.18 Kernel 5.5: version 05.52.18 https://www.insyde.com/security-pledge/SA-2022059

Use of a untrusted pointer allows tampering with SMRAM and OS memory in SdHostDriver and SdMmcDevice Use of a untrusted pointer allows tampering with SMRAM and OS memory in SdHostDriver and SdMmcDevice. This issue was discovered by Insyde during security review. It was fixed in: Kernel 5.0: version 05.09.17 Kernel 5.1: version 05.17.17 Kernel 5.2: version 05.27.17 Kernel 5.3: version 05.36.17 Kernel 5.4: version 05.44.17 Kernel 5.5: version 05.52.17 https://www.insyde.com/security-pledge/SA-2022062

Function IscsiMisc.c:IScsiHexToBin() in NetworkPkg/IScsiDxe does not correctly check the sizes of the input and output buffers, allowing an attacker who can control the input buffer to cause a buffer overflow in the destination buffer. Function IScsiHexToBin is used to decode strings passed as part of iSCSI Challenge-Handshake Authentication Protocol(CHAP), before authentication takes place. Thus an attacker, who can either inject himself in the communication between edk2 and the iSCSI target or control the iSCSI target used by edk2, can trigger this flaw and potentially execute code in the edk2 firmware.

Upstream bug: https://bugzilla.tianocore.org/showbug.cgi?id=3356

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