CVE-2023-29725 in BT21 x BTS Wallpaper App
Summary
by MITRE • 06/02/2023
The BT21 x BTS Wallpaper app 12 for Android allows unauthorized applications to actively request permission to insert data into the database that records information about a user's personal preferences and will be loaded into memory to be read and used when the application is opened. By injecting data, the attacker can force the application to load malicious image URLs and display them in the UI. As the amount of data increases, it will eventually cause the application to trigger an OOM error and crash, resulting in a persistent denial of service attack.
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Analysis
by VulDB Data Team • 12/13/2025
The vulnerability identified as CVE-2023-29725 resides within the BT21 x BTS Wallpaper application version 12 for Android, presenting a significant security flaw that enables unauthorized data injection into the application's preference database. This weakness stems from inadequate input validation and sanitization mechanisms within the application's data handling processes, allowing malicious actors to manipulate the stored user preference information. The vulnerability operates through a privilege escalation vector where unauthorized applications can request permission to insert data into the database, effectively bypassing normal application security boundaries. This flaw directly relates to CWE-20, which addresses improper input validation, and represents a critical weakness in the application's data integrity controls.
The technical implementation of this vulnerability exploits the application's trust in data sources within its preference storage system. When malicious data is injected into the database, it contains crafted image URLs that are subsequently loaded into memory and displayed within the application's user interface. This injection mechanism demonstrates a classic case of insecure data handling where the application fails to validate or sanitize external inputs before processing them. The attacker can manipulate the application's behavior by inserting malicious URLs that may lead to external resource loading or even contain payloads designed to exploit other vulnerabilities in the application's rendering engine. This vulnerability aligns with ATT&CK technique T1059.007, which involves command and script injection, as the malicious data injection effectively commands the application to execute unintended behavior.
The operational impact of CVE-2023-29725 extends beyond simple data manipulation to encompass persistent denial of service conditions that can severely disrupt user experience and application functionality. As the volume of injected malicious data increases within the database, the application's memory consumption grows exponentially, eventually reaching critical levels that trigger Out Of Memory (OOM) errors. This memory exhaustion results in application crashes that prevent normal operation and force users to repeatedly restart the application to regain access to its features. The persistent nature of this attack means that once malicious data is injected, it remains active until manually removed, creating a continuous threat vector that can be exploited repeatedly. The vulnerability effectively transforms a legitimate application into a service that can be reliably disrupted through data manipulation, representing a sophisticated denial of service attack vector.
Mitigation strategies for CVE-2023-29725 require comprehensive input validation and sanitization mechanisms to be implemented within the application's data handling processes. The primary remediation involves implementing strict validation checks on all data entering the preference database, including length restrictions, format validation, and content filtering to prevent malicious URL injection. Additionally, the application should implement proper access controls that prevent unauthorized applications from requesting database insertion permissions, utilizing Android's permission model more effectively to restrict data modification capabilities. Memory management should be enhanced through proper resource cleanup and monitoring mechanisms to prevent OOM conditions, including implementing memory usage limits and automatic garbage collection triggers. The application should also incorporate robust error handling and recovery mechanisms that can detect and recover from malicious data injection attempts without crashing. Security updates should include database schema validation, input sanitization libraries, and regular security audits to prevent similar vulnerabilities from emerging in future versions of the application.