CVE-2023-43513 in 4 Gen 1 Mobile Platform
Summary
by MITRE • 02/06/2024
Memory corruption while processing the event ring, the context read pointer is untrusted to HLOS and when it is passed with arbitrary values, may point to address in the middle of ring element.
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Analysis
by VulDB Data Team • 08/07/2025
This vulnerability exists within the memory management subsystem of a system where event rings are processed, specifically affecting the handling of context read pointers that are passed from an untrusted hypervisor level operating system to a trusted level operating system. The flaw manifests when the system processes event rings without proper validation of the context read pointer values, creating a memory corruption condition that can be exploited through arbitrary pointer values. The vulnerability stems from insufficient input sanitization and validation mechanisms that should normally prevent untrusted data from being directly used in memory operations. According to CWE-125, this represents an out-of-bounds read condition where the system fails to validate pointer values before dereferencing them, while CWE-787 indicates an out-of-bounds write vulnerability that can occur when arbitrary values are used to calculate memory addresses. The attack surface is particularly concerning in virtualized environments where hypervisor level components interact with trusted operating system components, as this represents a potential privilege escalation vector.
The technical implementation of this vulnerability involves the processing of event rings where memory addresses are calculated based on context read pointer values that originate from an untrusted source. When these pointers contain arbitrary values, they can point to memory locations that are not properly aligned with the expected ring element boundaries, causing the system to read or write data at unintended memory addresses. This memory corruption can lead to system instability, data leakage, or potentially allow an attacker to execute arbitrary code within the trusted operating system context. The vulnerability is particularly dangerous because it occurs at the interface between different security domains, where the hypervisor level operating system should not be able to directly influence or corrupt memory locations within the trusted level operating system. This aligns with ATT&CK technique T1068 which describes the exploitation of legitimate credentials or system access to escalate privileges, and T1211 which covers the exploitation of system vulnerabilities to gain unauthorized access.
The operational impact of this vulnerability extends beyond simple memory corruption, as it can enable attackers to manipulate system behavior through carefully crafted event ring data. An attacker who can control the context read pointer values can potentially cause the system to access memory regions that contain sensitive data, configuration information, or system code. This could lead to information disclosure, system compromise, or denial of service conditions that affect the overall security posture of the platform. The vulnerability's exploitation requires an attacker to have access to the event ring processing functionality, which may be available through legitimate system interfaces or through compromised components that can inject malicious event data. The attack can be particularly insidious in embedded systems or mobile platforms where the hypervisor and trusted operating system components share memory space and where such pointer validation is critical for maintaining system integrity. Mitigation strategies should focus on implementing robust pointer validation mechanisms, ensuring proper bounds checking of memory accesses, and applying security patches that address the root cause of the untrusted pointer handling in the event ring processing code.
The vulnerability represents a fundamental breakdown in security boundaries between different system levels, where data from an untrusted source should never be directly used without proper validation and sanitization. The memory corruption occurs due to the lack of proper input validation that should normally occur when processing data from potentially malicious sources. This creates a situation where an attacker can manipulate the system's memory layout through carefully crafted event ring data, potentially leading to privilege escalation or arbitrary code execution. The issue is particularly concerning in systems where the hypervisor and trusted operating system components are tightly integrated, as it represents a potential attack path that could be exploited to gain unauthorized access to system resources or to compromise the integrity of the trusted execution environment. Security controls should include mandatory input validation, memory address boundary checking, and proper separation of trusted and untrusted data processing components to prevent this type of vulnerability from being exploited.