CVE-2023-21396 in Android
Summary
by MITRE • 10/30/2023
In Activity Manager, there is a possible background activity launch due to a logic error in the code. This could lead to local escalation of privilege with User execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 09/06/2024
The vulnerability identified as CVE-2023-21396 resides within the Activity Manager component of Android operating systems, representing a critical logic flaw that enables unauthorized privilege escalation. This vulnerability specifically targets the background activity launch mechanism, where a malicious application can exploit a code logic error to execute activities in the background without proper authorization. The flaw exists in the system's permission handling and activity management processes, creating an unintended pathway for privilege elevation. According to CWE-284, this vulnerability demonstrates improper access control mechanisms that allow unauthorized entities to gain elevated privileges, while the ATT&CK framework categorizes this under privilege escalation techniques that leverage system-level vulnerabilities. The vulnerability affects Android versions prior to the security patch release, making it particularly concerning for devices that have not received timely updates.
The technical implementation of this vulnerability stems from a fundamental logic error in how the Activity Manager validates background activity launches. When an application attempts to initiate a background activity, the system's permission checking mechanism fails to properly enforce access controls, allowing malicious code to bypass normal security boundaries. This logic error creates a race condition or improper state validation where the system incorrectly assumes certain permissions or contexts, enabling unauthorized activities to execute with elevated privileges. The vulnerability specifically manifests when the system processes background activity requests without adequate verification of the requesting application's true permissions and capabilities. The flaw operates at the system level rather than the application level, making it particularly dangerous as it can be exploited by any application with basic user execution privileges, without requiring user interaction or additional malicious payloads.
The operational impact of CVE-2023-21396 extends beyond simple privilege escalation, creating potential for broader system compromise and data exposure. Once an attacker successfully exploits this vulnerability, they can execute malicious activities with elevated privileges, potentially accessing sensitive system resources, modifying critical system files, or establishing persistent backdoors. The lack of user interaction requirement makes this vulnerability particularly dangerous as it can be exploited silently in the background, making detection more difficult for both users and security monitoring systems. This vulnerability can enable attackers to perform actions such as accessing encrypted data, modifying system configurations, or creating new user accounts with administrative privileges. The background execution capability means that malicious activities can occur without the user's knowledge or consent, potentially leading to data theft, system corruption, or complete device compromise.
Mitigation strategies for CVE-2023-21396 primarily focus on timely patch deployment and system hardening measures. Device manufacturers and service providers should prioritize immediate security updates to address this vulnerability, as the flaw represents a significant risk to device security and user privacy. Users should ensure their devices receive and install all available security patches from their device manufacturers or carriers. Network administrators should monitor for exploitation attempts and implement additional security controls such as application whitelisting and behavioral monitoring to detect anomalous activity patterns. The vulnerability highlights the importance of proper access control implementation and the need for thorough code review processes to identify logic errors that could lead to privilege escalation. Security teams should also implement monitoring solutions that can detect unauthorized background activity launches and activity execution with elevated privileges, as these patterns may indicate exploitation attempts. Organizations should conduct vulnerability assessments to identify affected systems and ensure proper patch management processes are in place to prevent similar vulnerabilities from being exploited in the future.