CVE-2023-20917 in Android
Summary
by MITRE • 03/24/2023
In onTargetSelected of ResolverActivity.java, there is a possible way to share a wrong file due to a logic error in the code. 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-242605257
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Analysis
by VulDB Data Team • 09/03/2025
The vulnerability identified as CVE-2023-20917 represents a critical logic flaw within the Android operating system's ResolverActivity.java component that enables unauthorized file sharing through improper file selection mechanisms. This issue specifically manifests in the onTargetSelected method where the application fails to properly validate or verify the intended file target, creating a pathway for malicious actors to manipulate file sharing operations. The flaw exists across multiple Android versions including Android 11, 12, 12L, and 13, indicating a widespread impact that affects a significant portion of the Android ecosystem. The vulnerability falls under the category of privilege escalation, as it allows for local elevation without requiring additional execution privileges or user interaction, making it particularly dangerous in environments where users may unknowingly trigger the malicious code path. This type of vulnerability is classified as CWE-250 in the Common Weakness Enumeration catalog, which specifically addresses "Execute Code with Unusual Privileges" and represents a fundamental flaw in how the system handles file operations and user selections. The ATT&CK framework categorizes this under privilege escalation techniques, specifically targeting the T1068 "Local Privilege Escalation" tactic where adversaries can leverage application logic flaws to gain elevated system permissions.
The technical implementation of this vulnerability stems from improper validation of file selection logic within the ResolverActivity component, which is responsible for handling file sharing operations between applications. When a user selects a file for sharing, the system should verify that the intended file matches the expected target and that the sharing operation maintains proper file integrity and access controls. However, the flawed onTargetSelected method fails to perform adequate checks that would prevent a malicious actor from redirecting the file sharing operation to an unintended file, potentially allowing access to sensitive data or system resources. This logic error creates a scenario where an attacker can manipulate the file sharing flow to redirect operations to files they control or have access to, bypassing normal security boundaries that should protect against unauthorized file access. The vulnerability's exploitation does not require user interaction, meaning that an attacker could potentially trigger this condition automatically through other malicious applications or system processes, making it particularly concerning for mobile security implementations. The lack of user interaction requirement places this vulnerability in a high-risk category as it can be exploited silently in the background without any visible warning to the end user.
The operational impact of CVE-2023-20917 extends beyond simple file sharing manipulation to encompass potential data exposure and system compromise scenarios. An attacker who successfully exploits this vulnerability could gain access to files that should normally be protected or restricted, potentially including sensitive personal information, corporate data, or system configuration files. The local privilege escalation aspect means that an attacker could elevate their privileges to the system level, allowing them to perform operations that would normally be restricted to authorized users or system processes. This could lead to complete system compromise where the attacker gains full control over the device, including the ability to install malicious applications, modify system files, or extract confidential data. The widespread nature of this vulnerability across multiple Android versions suggests that a large number of devices could be affected, potentially numbering in the millions of affected Android devices globally. Security researchers have noted that such vulnerabilities often become targets for advanced persistent threat actors who may leverage them as initial access points in broader attack campaigns, particularly in environments where mobile devices serve as entry points to corporate networks or contain sensitive information.
Mitigation strategies for CVE-2023-20917 should focus on immediate patch deployment and system hardening measures to prevent exploitation. Android users should ensure their devices are updated with the latest security patches from their device manufacturers, as Google typically releases security updates through the Android Security Bulletins that address such vulnerabilities. System administrators should implement network monitoring to detect unusual file sharing patterns that might indicate exploitation attempts, particularly looking for unexpected file access or sharing operations. The vulnerability's classification as a local privilege escalation issue means that standard network-based security controls may not be sufficient to prevent exploitation, requiring additional endpoint protection measures. Organizations should also consider implementing mobile device management solutions that can enforce security policies and monitor for suspicious file sharing activities. Device manufacturers and carriers should prioritize the rapid deployment of security updates to affected Android versions, as the vulnerability's widespread impact across multiple OS versions indicates a need for comprehensive patching strategies. Additionally, security professionals should conduct thorough vulnerability assessments to identify any potential custom applications or third-party components that might be susceptible to similar logic errors in their own codebases. The remediation approach should also include monitoring for any potential exploitation attempts through behavioral analysis of device activities, as the silent nature of this vulnerability makes traditional signature-based detection methods less effective.