CVE-2022-42501 in Android
Summary
by MITRE • 12/16/2022
In HexString2Value of util.cpp, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-241231403References: N/A
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Analysis
by VulDB Data Team • 04/18/2025
The vulnerability identified as CVE-2022-42501 represents a critical out-of-bounds write flaw within the Android kernel's HexString2Value function located in util.cpp. This issue manifests as a missing bounds check that allows malicious input to overwrite memory regions beyond the intended buffer boundaries. The vulnerability resides in the kernel-level utility function responsible for converting hexadecimal string representations into their corresponding numerical values, making it a fundamental component in various kernel operations that process user-supplied data.
The technical exploitation of this vulnerability requires an attacker to provide specially crafted hexadecimal input that triggers the flawed conversion routine. When the HexString2Value function processes such input without proper bounds validation, it can overwrite adjacent memory locations, potentially corrupting kernel data structures or executing arbitrary code with elevated privileges. This flaw specifically targets the Android kernel's memory management and input validation mechanisms, creating a pathway for privilege escalation attacks that can ultimately result in complete system compromise. The vulnerability's classification as a local privilege escalation issue indicates that exploitation requires system execution privileges as a prerequisite, meaning an attacker must already have some level of access to the device before leveraging this weakness.
From an operational standpoint, this vulnerability presents significant security implications for Android devices as it enables attackers to gain elevated system privileges through carefully constructed input sequences. The attack vector does not require user interaction, making it particularly dangerous as it can be exploited automatically without user awareness or consent. The impact extends beyond simple data corruption, as successful exploitation could allow attackers to modify critical kernel components, install malicious software, or disable security features. This vulnerability aligns with CWE-129, which describes improper validation of array index or buffer bounds, and represents a clear violation of secure coding practices that should prevent buffer overflows in kernel-level code.
The mitigation strategies for CVE-2022-42501 primarily involve implementing proper bounds checking mechanisms within the HexString2Value function and ensuring that all buffer operations include adequate validation before memory access occurs. Android security teams should prioritize patching this vulnerability through kernel updates that incorporate proper input validation and bounds checking. Additionally, system administrators should monitor for any signs of exploitation attempts and consider implementing runtime protections such as stack canaries or address space layout randomization to reduce the effectiveness of potential exploitation attempts. The vulnerability's nature suggests that defensive programming techniques including input sanitization and memory protection mechanisms should be strengthened throughout the kernel codebase to prevent similar issues from occurring in other utility functions.