Insyde UEFI Firmware Vulnerabilities Allow Local Privilege Escalation

Insyde UEFI firmware contains multiple vulnerabilities that, if exploited, could allow a local attacker to gain administrator privileges. The attacker needs local access to the system to leverage these flaws. The specific vulnerabilities are not detailed in the advisory, but the impact allows for arbitrary code execution in the context of administrator privileges. This poses a significant risk to system integrity and confidentiality, as a successful exploit could lead to complete system compromise. Defenders should focus on detecting unauthorized modifications to the UEFI firmware or suspicious processes running within the UEFI environment.

Attack Chain

1. Attacker gains local access to the targeted system, either physically or via remote access with limited privileges.
2. Attacker identifies a vulnerable Insyde UEFI firmware version on the system.
3. Attacker leverages one of the unspecified vulnerabilities within the Insyde UEFI firmware.
4. Exploitation allows the attacker to inject and execute arbitrary code within the UEFI environment.
5. The injected code elevates the attacker’s privileges to administrator level.
6. Attacker uses elevated privileges to modify system settings, install malicious drivers, or compromise the operating system boot process.
7. Attacker persists on the system by modifying UEFI settings or implanting a bootkit.
8. Attacker executes arbitrary commands with administrator privileges.

Impact

Successful exploitation of these vulnerabilities allows a local attacker to execute arbitrary code with administrator privileges. This could lead to complete system compromise, including data theft, malware installation, and persistent access. The advisory does not specify the number of affected systems or sectors, but given the widespread use of Insyde UEFI firmware, the potential impact is significant.

Recommendation

• Monitor for unauthorized modifications to UEFI firmware using appropriate host-based security tools (file_event, registry_set).
• Implement stricter access controls to prevent unauthorized local access to systems.
• Deploy the Sigma rules to detect suspicious process creation originating from the UEFI environment (process_creation).