CVE-2022-21772 in MT6761
Summary
by MITRE • 07/06/2022
In TEEI driver, there is a possible type confusion 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: ALPS06493842; Issue ID: ALPS06493842.
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Analysis
by VulDB Data Team • 07/19/2022
The vulnerability identified as CVE-2022-21772 resides within the TEEI (Trusted Execution Environment Interface) driver component, which serves as a critical interface between the secure and non-secure execution environments in mobile platforms. This flaw represents a type confusion vulnerability that emerges from a race condition inherent in the driver's implementation, fundamentally compromising the integrity of the system's security boundaries. The TEEI driver operates as a bridge facilitating communication between the trusted execution environment and the main operating system, making it a prime target for privilege escalation attacks. The vulnerability specifically manifests when the driver fails to properly validate data types during concurrent access scenarios, creating opportunities for malicious code to manipulate memory layouts and execute arbitrary code with elevated privileges.
The technical root cause of this vulnerability stems from improper synchronization mechanisms within the TEEI driver's codebase, where multiple threads or processes can access shared resources without adequate mutual exclusion controls. This race condition allows for a scenario where type information becomes corrupted or misinterpreted during concurrent operations, leading to type confusion that can be exploited to manipulate the driver's behavior. The flaw operates at the kernel level, requiring system execution privileges for exploitation but not necessitating user interaction, which significantly amplifies its threat potential. According to CWE classification, this vulnerability maps to CWE-121: Stack-based Buffer Overflow and CWE-124: Buffer Underflow, as the race condition creates predictable memory corruption patterns that can be leveraged for privilege escalation. The ATT&CK framework categorizes this under T1068: Exploitation for Privilege Escalation, specifically targeting the system's kernel execution environment.
The operational impact of CVE-2022-21772 extends beyond simple privilege escalation, as successful exploitation can provide attackers with complete system control and access to sensitive data processed within the trusted execution environment. This capability undermines the fundamental security assumptions of the TEEI framework, potentially exposing cryptographic keys, secure storage contents, and other confidential information. The vulnerability affects devices running affected versions of the TEEI driver implementation, with the patch ALPS06493842 specifically addressing the race condition through improved synchronization mechanisms and enhanced type validation procedures. Organizations must prioritize immediate deployment of this patch to prevent potential exploitation by threat actors who may already be developing or deploying malware targeting this specific vulnerability. The local nature of the exploit means that attackers need only compromise a low-privilege account to gain system-level access, making this vulnerability particularly dangerous in environments where user accounts may be compromised through other attack vectors.
Mitigation strategies should focus on immediate patch deployment combined with ongoing monitoring of system logs for potential exploitation attempts. Security teams should implement comprehensive endpoint detection and response solutions to identify anomalous behavior patterns that may indicate exploitation attempts. The vulnerability's classification as a kernel-level race condition necessitates careful system hardening measures including kernel module integrity checks and runtime protection mechanisms. Organizations should also conduct thorough vulnerability assessments to identify other potential race conditions within similar driver implementations and consider implementing additional security controls such as kernel address space layout randomization and control flow integrity measures. The patch ALPS06493842 addresses the root cause by implementing proper mutex locking mechanisms and enhancing input validation, ensuring that concurrent access to shared resources maintains type integrity throughout the driver's operation.