CVE-2023-21097 in Android
Summary
by MITRE • 04/19/2023
In toUriInner of Intent.java, there is a possible way to launch an arbitrary activity due to a confused deputy. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11 Android-12 Android-12L Android-13Android ID: A-261858325
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Analysis
by VulDB Data Team • 09/11/2025
The vulnerability identified as CVE-2023-21097 resides within the Android operating system's intent handling mechanism, specifically in the toUriInner method of the Intent.java class. This flaw represents a confused deputy problem where an application can potentially manipulate the intent resolution process to launch arbitrary activities without proper authorization. The vulnerability affects multiple Android versions including Android 11, 12, 12L, and 13, indicating a widespread impact across the Android ecosystem. The confused deputy scenario occurs when a malicious application leverages the flawed intent resolution to bypass normal access controls and execute unauthorized activities.
The technical implementation of this vulnerability stems from improper validation of intent parameters during URI construction. When the toUriInner method processes intent objects, it fails to adequately verify the authenticity and intended target of the activity being launched. This allows an attacker to manipulate the intent structure in such a way that the system resolves to an unintended target activity, potentially one that would normally require elevated privileges or special permissions. The flaw essentially enables a form of privilege escalation where a regular application can invoke activities that should be restricted to system-level or privileged applications.
The operational impact of this vulnerability is significant as it enables local privilege escalation without requiring any additional execution privileges or user interaction. This means that an attacker with a regular application running on the device can potentially gain elevated privileges and access restricted system functions. The attack vector does not require user interaction, making it particularly dangerous as it can be exploited automatically without any user awareness or consent. The vulnerability essentially allows an application to masquerade as another application or system component, leading to unauthorized access and potential system compromise.
From a cybersecurity perspective, this vulnerability aligns with CWE-284 (Improper Access Control) and represents a classic example of privilege escalation through confused deputy attacks. The ATT&CK framework categorizes this under privilege escalation techniques, specifically leveraging application weaknesses to gain higher system privileges. The vulnerability also relates to Android's security model where proper intent resolution and activity launching should be strictly controlled to prevent unauthorized access to system resources. Organizations should prioritize patching this vulnerability immediately as it represents a critical security risk that could be exploited to gain unauthorized access to sensitive system functions and potentially compromise entire devices.
Mitigation strategies should focus on applying the latest security patches provided by Google for affected Android versions. System administrators should also implement application whitelisting policies and monitor for suspicious intent resolution patterns. Additionally, regular security audits of applications that handle intents and activities should be conducted to identify potential exploitation vectors. The vulnerability underscores the importance of proper input validation and intent verification mechanisms in mobile operating systems, particularly in environments where multiple applications interact through the intent system. Organizations should also consider implementing mobile device management solutions that can help detect and prevent exploitation attempts of such vulnerabilities.