CVE-2020-0442 in Android
Summary
by MITRE • 11/10/2020
In Message and toBundle of Notification.java, there is a possible UI slowdown or crash due to improper input validation. This could lead to remote denial of service if a malicious contact file is received, with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-10 Android-11 Android-8.0 Android-8.1 Android-9Android ID: A-147358092
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Analysis
by VulDB Data Team • 12/04/2020
The vulnerability identified as CVE-2020-0442 resides within the Android notification system, specifically in the Message and toBundle methods of the Notification.java file. This represents a classic case of insufficient input validation that can be exploited to cause unintended system behavior. The flaw manifests when the Android system processes notification data structures, particularly when handling contact information or notification metadata that contains malformed or unexpectedly formatted input. The vulnerability stems from the Android framework's failure to properly sanitize or validate input parameters before processing them into notification bundles, creating a pathway for maliciously crafted data to disrupt normal system operations.
The technical nature of this vulnerability aligns with CWE-20, which describes improper input validation, and can be categorized under the broader ATT&CK technique T1499.100 for network denial of service. The flaw enables a remote attacker to craft a specially formatted contact file or notification payload that, when processed by the Android notification system, triggers excessive resource consumption or invalid memory operations. The vulnerability specifically affects Android versions 8.0, 8.1, 9, 10, and 11, indicating a widespread impact across multiple Android release lines. The exploit requires no additional privileges beyond the ability to send a notification or contact file, making it particularly dangerous as it can be triggered through standard communication channels without user interaction.
From an operational perspective, this vulnerability creates a significant risk of denial of service attacks that can affect the notification system's responsiveness and overall device stability. When exploited, the malicious input can cause the notification manager to enter an infinite loop or consume excessive CPU cycles during the processing of notification bundles, potentially leading to complete system unresponsiveness or application crashes. The impact extends beyond simple inconvenience as notification services are fundamental to Android's user experience and system functionality, affecting everything from security alerts to application communications. Attackers could leverage this vulnerability to disrupt critical services or create persistent denial of service conditions that require device restarts to resolve.
The mitigation strategies for CVE-2020-0442 primarily involve applying the security patches released by Google as part of their Android security updates. Organizations should ensure that all Android devices are updated to the latest security patches, particularly those released in the April 2020 security bulletin. Network administrators should implement monitoring for unusual notification traffic patterns that might indicate exploitation attempts, though the vulnerability's remote nature without user interaction makes proactive detection challenging. Device manufacturers should also consider implementing additional input sanitization layers in their custom Android implementations. The vulnerability highlights the importance of robust input validation in system-level components and demonstrates how seemingly minor flaws in notification handling can create significant security risks. Security teams should also consider the broader implications of similar vulnerabilities in other Android system components and implement comprehensive input validation policies across all notification and data processing pathways to prevent similar issues from arising in the future.