CVE-2022-20558 in Android
Summary
by MITRE • 12/16/2022
In registerReceivers of DeviceCapabilityListener.java, there is a possible way to change preferred TTY mode due to a permissions bypass. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-13Android ID: A-236264289
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Analysis
by VulDB Data Team • 04/22/2026
The vulnerability identified as CVE-2022-20558 resides within the Android operating system's DeviceCapabilityListener.java component, specifically in the registerReceivers method. This flaw represents a critical permissions bypass that enables unauthorized modification of the preferred TTY (Teletypewriter) mode configuration. The TTY mode configuration controls how terminal devices communicate with the system and can significantly impact the underlying communication channels used by various system components. The vulnerability is particularly concerning because it allows for local privilege escalation without requiring any additional execution privileges or user interaction, making it highly exploitable within the Android security model.
The technical implementation of this vulnerability stems from improper access control mechanisms within the DeviceCapabilityListener.java file. When the registerReceivers method processes incoming broadcast intents related to device capability changes, it fails to adequately validate the permissions of the calling process attempting to modify the TTY mode settings. This permission bypass occurs because the system does not properly enforce the required security checks that should normally prevent unauthorized modification of system-level communication parameters. The flaw essentially allows any malicious application with basic system access to manipulate the TTY mode configuration, which can then be leveraged to gain elevated privileges within the system.
From an operational perspective, this vulnerability creates a significant risk for Android devices as it provides a pathway for local privilege escalation that requires no additional user interaction or elevated permissions. The exploitation process is straightforward since the attacker only needs to trigger the appropriate broadcast intent that would normally be restricted to system-level components. Once successfully exploited, the modified TTY mode can be used to establish more persistent access or to facilitate further exploitation techniques that rely on specific terminal communication behaviors. This vulnerability directly impacts the Android 13 operating system and affects all devices running this version, making it particularly concerning given the widespread adoption of this Android release.
The security implications extend beyond simple privilege escalation as this vulnerability can be used as a stepping stone for more sophisticated attacks within the Android security architecture. According to CWE classification, this vulnerability maps to CWE-284: Improper Access Control, which specifically addresses insufficient access control mechanisms that allow unauthorized users to access resources or perform actions they should not be permitted to execute. The ATT&CK framework would categorize this under privilege escalation techniques, specifically T1068: Exploitation for Privilege Escalation, where the initial access point is through a permissions bypass rather than traditional exploitation methods. Organizations and users should be particularly concerned about this vulnerability as it represents a fundamental weakness in Android's permission model that could be exploited by malicious applications or attackers with limited initial access to the device.
Mitigation strategies for CVE-2022-20558 should focus on immediate patch deployment from Google, as this vulnerability affects Android 13 and requires system-level updates to resolve the underlying access control issues. Device manufacturers should prioritize rolling out security patches to affected devices and users should ensure their devices are updated as soon as patches become available. Additionally, security monitoring should include detection of unusual broadcast intent patterns that might indicate exploitation attempts, and system administrators should consider implementing additional access control measures to limit the potential impact of such vulnerabilities in enterprise environments. The vulnerability also highlights the importance of proper input validation and access control implementation in system-level components, particularly those handling device capability configurations that can be leveraged for privilege escalation.