CVE-2022-21774 in MT6761
Summary
by MITRE • 07/06/2022
In TEEI driver, there is a possible use after free due to a race condition. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS06641447; Issue ID: ALPS06641447.
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Analysis
by VulDB Data Team • 07/19/2022
The vulnerability identified as CVE-2022-21774 resides within the Trusted Execution Environment Interface driver component of Android-based systems, specifically affecting devices utilizing ARM TrustZone technology. This issue represents a critical race condition flaw that manifests in the improper handling of memory management operations within the TEEI driver context. The vulnerability occurs when the driver fails to properly synchronize access to shared resources during concurrent operations, creating temporal gaps where memory objects may be prematurely freed while still being referenced by other system components.
The technical exploitation of this vulnerability stems from a use-after-free condition that emerges due to inadequate mutex or semaphore implementation in the driver's memory management routines. When multiple threads or processes attempt to access the same memory region simultaneously, the race condition allows one thread to free a memory object while another thread continues to reference it, leading to undefined behavior. This particular flaw is classified under CWE-416 as a Use After Free vulnerability, which directly maps to the TEEI driver's failure to maintain proper reference counting and memory lifecycle management. The vulnerability requires system-level execution privileges for exploitation, indicating that an attacker must already possess elevated privileges to leverage this weakness, though the ultimate outcome would result in privilege escalation to system level.
The operational impact of this vulnerability extends beyond simple memory corruption, as it creates a pathway for local privilege escalation that could enable attackers to gain complete system control. The exploitation process does not require user interaction, making it particularly dangerous as it can be triggered automatically through system processes or malicious applications running with appropriate privileges. When successfully exploited, the vulnerability allows an attacker to execute arbitrary code with system-level privileges, potentially enabling full device compromise, data exfiltration, or persistence mechanisms. This aligns with ATT&CK technique T1068 which covers "Local Privilege Escalation" and represents a significant threat to device security and user privacy.
Mitigation strategies for CVE-2022-21774 should prioritize the immediate application of the vendor-provided patch identified by patch ID ALPS06641447 and issue ID ALPS06641447. System administrators and device manufacturers should conduct comprehensive testing of the patch in their specific environments to ensure compatibility and prevent potential regressions in system functionality. Additionally, implementing runtime monitoring and memory integrity checks can provide early detection capabilities for similar race condition vulnerabilities. Organizations should also consider deploying security frameworks that can detect anomalous memory access patterns and unauthorized privilege escalation attempts. The patch implementation must include thorough regression testing to ensure that the fix does not introduce new stability issues or performance degradation in the TEEI driver operations. Security teams should monitor for any potential bypass techniques or related vulnerabilities that may emerge from similar race condition patterns in other kernel components or drivers within the Trusted Execution Environment ecosystem.