CVE-2017-11087 in Android
Summary
by MITRE
libOmxVenc in Android for MSM, Firefox OS for MSM, and QRD Android copies the output buffer to an application with the "filled length", which is larger than the output buffer's actual size, leading to an information disclosure problem in the context of mediaserver.
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Analysis
by VulDB Data Team • 01/18/2020
The vulnerability identified as CVE-2017-11087 affects the libOmxVenc component across multiple Android variants including MSM, Firefox OS for MSM, and QRD Android systems. This issue resides within the mediaserver context where the component improperly handles buffer management during video encoding operations. The flaw manifests when the system copies output buffer data to an application, but uses a "filled length" value that exceeds the actual buffer size, creating a condition where data extends beyond intended boundaries.
The technical implementation of this vulnerability stems from improper buffer boundary checking within the OMX (OpenMAX) video encoding framework. When libOmxVenc processes video encoding tasks, it calculates and reports a filled length that encompasses more data than the physical buffer can contain. This discrepancy occurs during the buffer copying operation between the mediaserver and the application layer, where the reported filled length parameter is not properly validated against the actual buffer dimensions. The issue specifically impacts the mediaserver process which handles multimedia encoding tasks for various applications, creating a potential information disclosure vector.
The operational impact of this vulnerability extends beyond simple data corruption, as it enables unauthorized information disclosure through memory content leakage. When applications attempt to read the output buffer, they may inadvertently access memory regions that contain sensitive data from previous operations, system memory, or other processes. This information disclosure can potentially expose cryptographic keys, user data, or system internals that should remain protected. The vulnerability is particularly concerning in the context of mediaserver as this component typically operates with elevated privileges and handles multimedia data from multiple applications, amplifying the potential scope of information leakage.
This vulnerability aligns with CWE-121, which addresses stack buffer overflow conditions, and CWE-125, which covers out-of-bounds read vulnerabilities. The flaw also maps to ATT&CK technique T1059.007 for command and scripting interpreter, as exploitation could potentially enable adversaries to extract sensitive information that might be used to facilitate further attacks. The attack surface is particularly relevant for mobile devices where mediaserver processes handle multimedia data from various sources, including web content and application data streams. Organizations should implement immediate mitigations including buffer size validation checks, proper boundary enforcement, and regular security updates to prevent exploitation of this information disclosure vulnerability that could compromise user privacy and system integrity.