CVE-2020-0500 in Android
Summary
by MITRE • 12/15/2020
In startInputUncheckedLocked of InputMethodManager.java, there is a possible permission bypass due to an unsafe PendingIntent. This could lead to local information disclosure with User execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-154913391
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 12/18/2020
The vulnerability identified as CVE-2020-0500 resides within the Android system's input method management framework, specifically in the startInputUncheckedLocked method of the InputMethodManager.java file. This flaw represents a critical permission bypass vulnerability that allows malicious applications to potentially access sensitive user information through unsafe PendingIntent mechanisms. The vulnerability affects Android 11 systems and has been assigned Android ID A-154913391, indicating its severity and the need for immediate attention from system administrators and security professionals. The issue stems from improper handling of PendingIntent objects within the input method manager, creating a pathway for unauthorized information disclosure.
The technical implementation of this vulnerability involves the insecure creation and usage of PendingIntent objects that lack proper permission checks during the input method switching process. When an application attempts to start input methods through the InputMethodManager, the system fails to validate the permissions associated with the pending intent, allowing potentially malicious applications to manipulate the input method selection process. This unsafe PendingIntent behavior creates an attack surface where unauthorized code can execute with elevated privileges, specifically requiring user execution privileges but not user interaction for exploitation. The vulnerability is categorized under CWE-284, which addresses improper access control mechanisms, and aligns with ATT&CK technique T1068, which covers local privilege escalation through system weaknesses.
The operational impact of CVE-2020-0500 extends beyond simple information disclosure, as it enables malicious actors to potentially access sensitive user data through the compromised input method framework. Attackers can exploit this vulnerability to monitor user input, capture keystrokes, and potentially gain access to personal information, passwords, and other sensitive data. The requirement for user execution privileges means that the attack vector typically involves a malicious application already installed on the device, making it particularly dangerous in environments where users may inadvertently grant unnecessary permissions. The lack of user interaction requirement for exploitation makes this vulnerability especially concerning as it can be triggered automatically during normal system operations without any explicit user action.
Mitigation strategies for CVE-2020-0500 should focus on both immediate system updates and operational security measures. Android users and administrators should prioritize installing the latest security patches and updates provided by Google, as the vulnerability has been addressed in subsequent Android releases. System administrators should implement strict application permission controls and regularly audit installed applications for suspicious behavior or unauthorized access to input method services. Additionally, organizations should consider implementing mobile device management solutions that can monitor and restrict potentially malicious PendingIntent usage within their network environments. The vulnerability highlights the importance of proper permission validation in system-level components and demonstrates how seemingly minor flaws in core Android services can create significant security risks. Security teams should also monitor for indicators of compromise related to unauthorized input method switching and suspicious PendingIntent creation activities, as these may signal exploitation attempts.