CVE-2022-20576 in Android
Summary
by MITRE • 12/16/2022
In externalOnRequest of rilapplication.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-239701761References: N/A
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Analysis
by VulDB Data Team • 04/22/2026
The vulnerability identified as CVE-2022-20576 resides within the Android kernel's RIL (Radio Interface Layer) implementation, specifically in the externalOnRequest function located in rilapplication.cpp. This flaw represents a critical security weakness that could enable malicious actors to achieve local privilege escalation, ultimately gaining system-level execution privileges. The vulnerability manifests as an out-of-bounds write condition that occurs when the system fails to perform proper bounds checking on array or buffer operations. Such missing validation creates an opportunity for attackers to overwrite adjacent memory locations, potentially corrupting critical system data structures or executing arbitrary code with elevated privileges. The Android ID A-239701761 specifically identifies this issue within the kernel's telephony subsystem, highlighting its impact on mobile device security foundations.
The technical implementation of this vulnerability stems from insufficient input validation within the RIL application's request handling mechanism. When processing external requests, the system does not properly verify array boundaries before writing data, creating a scenario where attacker-controlled input can cause memory corruption beyond intended buffer limits. This type of flaw falls under CWE-129, which specifically addresses insufficient validation of length of inputs, and more broadly relates to CWE-787, concerning out-of-bounds write conditions. The vulnerability's exploitation requires only local system access since no user interaction is necessary, making it particularly dangerous in environments where unauthorized local access is possible. Attackers can leverage this weakness to manipulate memory contents and potentially execute code with system privileges, effectively bypassing normal security boundaries that protect against unauthorized access to critical system resources.
The operational impact of CVE-2022-20576 extends beyond simple privilege escalation, as it represents a fundamental weakness in Android's kernel-level security architecture. This vulnerability affects Android kernel implementations, potentially compromising the integrity of mobile device security models and enabling attackers to gain unauthorized access to sensitive system functions. The implications are significant for mobile device security, as it could allow unauthorized parties to execute malicious code with system-level privileges, potentially leading to complete device compromise. The lack of user interaction requirements makes this vulnerability particularly concerning for mobile environments where devices may be accessed by unauthorized individuals. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and could be leveraged as part of broader attack chains targeting mobile device security boundaries. The vulnerability's presence in the RIL subsystem means that it affects core telephony functionality, potentially enabling attackers to manipulate cellular communications or access sensitive information stored within the device's telephony stack.
Mitigation strategies for CVE-2022-20576 should focus on implementing proper bounds checking mechanisms within the RIL application's externalOnRequest function and ensuring that all array operations include comprehensive validation. System administrators should prioritize applying security patches released by Android vendors and device manufacturers to address this kernel-level vulnerability. The implementation of memory safety checks and input validation should be enforced throughout the RIL subsystem to prevent similar out-of-bounds write conditions. Additionally, device manufacturers should consider implementing runtime protections and address space layout randomization to make exploitation more difficult. Regular security audits of kernel components and telephony stack implementations should be conducted to identify and remediate similar vulnerabilities before they can be exploited. Organizations should also implement monitoring solutions to detect anomalous behavior patterns that might indicate exploitation attempts, particularly focusing on memory corruption indicators and privilege escalation events within mobile device security frameworks.