CVE-2020-0476 in Android
Summary
by MITRE • 12/15/2020
In onNotificationRemoved of Assistant.java, there is a possible leak of sensitive information to logs. This could lead to local information disclosure with System execution privileges required. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-162014574
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Analysis
by VulDB Data Team • 12/18/2020
The vulnerability identified as CVE-2020-0476 resides within the Android operating system's Assistant.java component, specifically in the onNotificationRemoved method. This flaw represents a sensitive information disclosure issue that could potentially allow unauthorized access to confidential data stored in system logs. The vulnerability is classified under CWE-200, which addresses "Information Exposure," and falls within the broader category of information leakage vulnerabilities that pose significant security risks to mobile platforms. The affected Android version is Android 11, with the specific Android ID A-162014574 documenting this particular security gap.
The technical implementation of this vulnerability stems from improper handling of sensitive data within the notification removal process. When notifications are removed from the system, the Assistant.java component fails to adequately sanitize or filter sensitive information before it might be logged. This oversight creates a potential information disclosure channel where system-level processes could inadvertently expose confidential data through log files that are accessible to processes running with System execution privileges. The flaw demonstrates a classic case of insufficient input validation and output sanitization, where sensitive parameters or data elements are not properly stripped or encoded before being processed for logging purposes.
The operational impact of this vulnerability extends beyond simple information leakage, as it requires System execution privileges for exploitation, indicating that an attacker with elevated privileges could leverage this flaw to access sensitive system information. This requirement for system-level access does not diminish the severity of the vulnerability, as it represents a privilege escalation vector that could be combined with other exploits to gain deeper system access. The potential for local information disclosure means that an attacker could extract confidential data such as user credentials, personal information, or system configurations that are typically protected from casual access. This vulnerability aligns with ATT&CK technique T1005, which covers "Data from Local System," and demonstrates how seemingly minor logging flaws can create significant security implications.
Mitigation strategies for CVE-2020-0476 should focus on comprehensive code review and input sanitization within the Assistant.java component, particularly around notification handling and logging operations. Android security patches would typically address this by implementing proper data sanitization before logging sensitive information, ensuring that any potentially confidential data is either filtered out or properly encoded before being written to system logs. Organizations should also implement robust log management practices, including access controls on log files and regular monitoring for anomalous logging patterns that might indicate exploitation attempts. The fix would likely involve modifying the onNotificationRemoved method to explicitly sanitize or remove sensitive data elements before any logging operations occur, thereby preventing the unintended exposure of confidential information through system logs. This vulnerability underscores the critical importance of secure coding practices and comprehensive security testing of system-level components that handle user data and system information.