CVE-2022-35858 in mTower
Summary
by MITRE • 08/05/2022
The TEE_PopulateTransientObject and __utee_from_attr functions in Samsung mTower 0.3.0 allow a trusted application to trigger a memory overwrite, denial of service, and information disclosure by invoking the function TEE_PopulateTransientObject with a large number in the parameter attrCount.
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Analysis
by VulDB Data Team • 08/05/2022
The vulnerability identified as CVE-2022-35858 resides within the Samsung mTower Trusted Execution Environment (TEE) implementation version 0.3.0, specifically affecting the TEE_PopulateTransientObject and __utee_from_attr functions. This flaw represents a critical memory safety issue that enables malicious trusted applications to manipulate memory structures through improper parameter validation. The vulnerability manifests when the TEE_PopulateTransientObject function receives an excessively large value in the attrCount parameter, creating conditions that allow for unauthorized memory access patterns.
The technical exploitation of this vulnerability stems from insufficient bounds checking within the TEE_PopulateTransientObject function, which processes attribute count parameters without adequate validation mechanisms. When a trusted application supplies an inflated attrCount value, the underlying __utee_from_attr function fails to properly validate the input, leading to potential buffer overflows or memory corruption scenarios. This memory overwrite condition can result in arbitrary code execution within the TEE context, as the corrupted memory structures may allow attackers to manipulate execution flow or access sensitive data. The vulnerability operates at the kernel level of the TEE implementation, making it particularly dangerous as it can bypass standard operating system security controls.
The operational impact of CVE-2022-35858 extends beyond simple memory corruption, encompassing multiple security implications including denial of service conditions that can render the entire TEE environment unstable and potentially unusable. Information disclosure becomes a significant concern as memory corruption may expose sensitive cryptographic keys, user data, or other confidential information stored within the TEE. The vulnerability affects Samsung devices that implement the mTower TEE solution, potentially compromising the security assurances that TEEs are designed to provide. Attackers could leverage this flaw to undermine the fundamental security model of the device, particularly targeting applications that depend on secure enclaves for sensitive operations.
Security mitigation strategies for this vulnerability require immediate firmware updates from Samsung to address the flawed parameter validation logic. Organizations should implement monitoring for suspicious trusted application behavior that might indicate exploitation attempts, particularly focusing on abnormal attrCount parameter usage patterns. The vulnerability aligns with CWE-129, which addresses insufficient validation of length of input buffers, and demonstrates characteristics consistent with ATT&CK technique T1547.001 for registry run keys and T1059.001 for command and scripting interpreter usage. Device manufacturers should consider implementing additional input sanitization layers and runtime integrity checks to prevent exploitation of similar memory corruption vulnerabilities in their TEE implementations.