CVE-2020-0136 in Android
Summary
by MITRE
In multiple locations of Parcel.cpp, there is a possible out-of-bounds write due to an integer overflow. This could lead to local escalation of privilege in the system server with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-10Android ID: A-120078455
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Analysis
by VulDB Data Team • 06/12/2020
The vulnerability identified as CVE-2020-0136 represents a critical integer overflow flaw within the Android system server's parcel handling mechanism. This issue manifests in multiple locations within the Parcel.cpp file, where improper integer overflow handling creates opportunities for out-of-bounds write conditions. The vulnerability specifically affects Android 10 operating system versions and is catalogued under Android ID A-120078455. The flaw resides in the system server's ability to process parcel data structures, which are fundamental components used for inter-process communication and data serialization within the Android framework. When the system processes malformed or crafted parcel data, the integer overflow condition can occur during buffer size calculations or memory allocation operations.
The technical exploitation of this vulnerability leverages the integer overflow to manipulate memory layout and potentially overwrite adjacent memory regions. This occurs when the system server processes parcel data containing maliciously crafted integer values that, when used in arithmetic operations, exceed the maximum representable value for the integer type. The resulting overflow can cause subsequent memory operations to write data beyond the intended buffer boundaries, potentially corrupting critical system structures or executing arbitrary code. The vulnerability's classification as a local privilege escalation vector indicates that an attacker with local system access could leverage this flaw to gain elevated privileges without requiring additional execution privileges or user interaction. This makes the vulnerability particularly dangerous as it can be exploited by any process running with system-level permissions or by malicious applications that have already gained local access to the device.
The operational impact of CVE-2020-0136 extends beyond simple memory corruption, as it provides a pathway for attackers to escalate their privileges within the Android system. This vulnerability can be exploited to gain root-level access to the device, potentially allowing full control over system operations, data access, and application management. The lack of user interaction requirement means that exploitation can occur automatically when the system processes malicious parcel data, making it particularly concerning for automated attacks. The vulnerability affects the core system server functionality, which handles critical system operations and inter-process communication, making successful exploitation particularly damaging to system integrity and security posture. From a cybersecurity perspective, this vulnerability aligns with CWE-190, which describes integer overflow conditions, and represents a significant risk for attackers following the MITRE ATT&CK framework's privilege escalation techniques, specifically targeting system-level processes and memory corruption vulnerabilities.
Mitigation strategies for CVE-2020-0136 should prioritize immediate patching of affected Android 10 systems through official security updates from device manufacturers. Organizations should implement network monitoring to detect potential exploitation attempts through abnormal parcel data processing patterns and establish robust system integrity monitoring to identify unauthorized privilege escalation activities. Security teams should also conduct thorough vulnerability assessments to identify any custom applications or system modifications that might interact with the affected parcel handling code. Device manufacturers and security vendors should maintain comprehensive incident response procedures to address potential exploitation attempts, while users should ensure all devices are updated with the latest security patches. The vulnerability demonstrates the critical importance of secure coding practices in system-level components and highlights the need for rigorous code review processes to identify integer overflow conditions in memory management operations. Additionally, implementing proper input validation and bounds checking mechanisms in parcel processing code can prevent similar vulnerabilities from emerging in future system versions.