CVE-2022-20504 in Android
Summary
by MITRE • 12/16/2022
In multiple locations of DreamManagerService.java, there is a missing permission check. This could lead to local escalation of privilege and dismissal of system dialogs with User execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-13Android ID: A-225878553
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Analysis
by VulDB Data Team • 04/18/2026
The vulnerability identified as CVE-2022-20504 resides within the DreamManagerService.java component of Android 13 systems, representing a critical permission bypass flaw that enables local privilege escalation. This issue manifests across multiple locations within the service implementation where essential permission checks are absent, creating exploitable pathways for malicious actors with user-level execution privileges to elevate their privileges to system level. The vulnerability's classification aligns with CWE-284, which specifically addresses improper access control mechanisms, and falls under the ATT&CK technique T1068 for local privilege escalation through improper access control.
The technical flaw stems from the absence of proper authorization verification within the DreamManagerService, which is responsible for managing dream (screensaver) components in Android systems. When applications or processes attempt to interact with dream manager functionality, the service fails to validate whether the calling entity possesses the necessary permissions to perform the requested operations. This missing validation allows unprivileged users to manipulate system dialogs and execute privileged operations that should only be accessible to system-level components or applications with appropriate permissions.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables attackers to dismiss system dialogs that typically serve as security warnings or notifications to users. This capability can be leveraged to bypass important security prompts, potentially allowing for more sophisticated attacks such as overlay attacks, credential harvesting, or other malicious activities that rely on user interaction being suppressed. The vulnerability requires only user execution privileges for exploitation, making it particularly dangerous as it can be triggered by any application running with standard user permissions rather than requiring more privileged access.
From a security perspective, this vulnerability represents a significant weakening of Android's security model, as it undermines the principle of least privilege by allowing unauthorized access to system-level functionality. The attack vector does not require user interaction, which means it can be exploited automatically without any human intervention, making it particularly concerning for mobile environments where users may not be aware of such background processes. Organizations and security teams should consider implementing additional monitoring for unauthorized access patterns and ensure proper patch management to address this vulnerability.
The remediation approach for this vulnerability involves implementing proper permission checks throughout the DreamManagerService.java codebase, ensuring that all operations require appropriate authorization before execution. This includes validating that calling processes possess the necessary permissions to access dream manager functionality and properly handling cases where unauthorized access attempts occur. Security hardening measures should also include regular code reviews to identify similar permission bypass issues in other system components, as well as implementing proper logging and monitoring to detect unauthorized access attempts. The fix should align with Android's security framework requirements and maintain compatibility with existing system functionality while strengthening access controls.