CVE-2016-6762 in Android
Summary
by MITRE
An elevation of privilege vulnerability in the libziparchive library could enable a local malicious application to execute arbitrary code within the context of a privileged process. This issue is rated as High because it could be used to gain local access to elevated capabilities, which are not normally accessible to a third-party application. Product: Android. Versions: 5.0.2, 5.1.1, 6.0, 6.0.1, 7.0. Android ID: A-31251826.
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Analysis
by VulDB Data Team • 07/20/2020
The CVE-2016-6762 vulnerability represents a critical elevation of privilege flaw within the libziparchive library component of Android operating systems. This vulnerability affects multiple Android versions including 5.0.2, 5.1.1, 6.0, 6.0.1, and 7.0, making it a widespread concern across the Android ecosystem. The issue stems from improper handling of zip archive files within the system's archive processing capabilities, creating a pathway for malicious applications to exploit the system's privilege model. The vulnerability's classification as High severity reflects its potential to allow local attackers to execute arbitrary code with elevated privileges, effectively bypassing normal security boundaries that protect privileged system processes.
The technical flaw manifests in the libziparchive library's insufficient validation and handling of malformed or specially crafted zip archive files. When a malicious application attempts to process such archives, the library fails to properly sanitize input data, leading to memory corruption or control flow manipulation. This vulnerability operates at the system level where the library executes with elevated privileges, allowing the malicious code to potentially leverage this privilege escalation to gain access to system resources, modify protected files, or execute commands with root-level permissions. The attack vector typically involves an application that processes zip files through the libziparchive library, which could be triggered by user interaction or automatic processing of downloaded content.
The operational impact of CVE-2016-6762 extends beyond simple privilege escalation, as it provides attackers with a potential gateway to complete system compromise. Once an attacker successfully exploits this vulnerability, they can execute arbitrary code within the context of privileged processes, potentially gaining access to sensitive system data, modifying critical system files, or establishing persistent backdoors. The vulnerability's local nature means that it requires the attacker to already have a presence on the device through a malicious application, but once exploited, it can provide extensive access to system capabilities normally restricted to system-level processes. This makes the vulnerability particularly dangerous in environments where users may unknowingly install malicious applications or when applications have legitimate access to file processing functionality.
Security professionals should note that this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and may also relate to CWE-122, heap-based buffer overflow conditions, depending on the specific implementation details. The attack pattern associated with this vulnerability follows the MITRE ATT&CK framework's privilege escalation techniques, specifically targeting the 'Exploitation for Privilege Escalation' and 'Execution' phases. Organizations should prioritize immediate patching of affected Android versions and implement monitoring for suspicious file processing activities. Additionally, application developers should ensure their applications properly validate and sanitize all input data, particularly when processing zip archives, and consider implementing additional security measures such as sandboxing or restricted file access permissions to limit potential impact. The vulnerability underscores the importance of secure coding practices in system libraries and demonstrates how seemingly innocuous functionality can become a critical security weakness when proper input validation and privilege management are not implemented.