CVE-2017-6276 in Android
Summary
by MITRE
NVIDIA mediaserver contains a vulnerability where it is possible a use after free malfunction can occur due to an incorrect bounds check which could enable unauthorized code execution and possibly lead to elevation of privileges. This issue is rated as high. Product: Android. Version: N/A. Android: A-63802421. References: N-CVE-2017-6276.
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Analysis
by VulDB Data Team • 01/25/2021
The vulnerability identified as CVE-2017-6276 resides within NVIDIA's mediaserver component, a critical Android system service responsible for handling multimedia processing operations. This flaw manifests as a use-after-free condition that occurs when the mediaserver fails to properly validate bounds during memory management operations. The improper bounds checking mechanism creates a scenario where freed memory regions can be accessed or reused by subsequent operations, potentially leading to arbitrary code execution. The vulnerability specifically affects Android devices utilizing NVIDIA's media processing capabilities, making it particularly concerning for mobile device security. The issue is classified as high severity due to its potential for privilege escalation, which could allow attackers to gain elevated system privileges beyond normal user limitations. This type of vulnerability falls under the CWE-416 category of "Use After Free" which represents a well-documented class of memory corruption vulnerabilities that have been exploited in numerous security incidents. The attack surface is particularly significant as mediaserver components typically operate with elevated privileges and handle sensitive multimedia data processing tasks.
The technical exploitation of this vulnerability requires careful manipulation of the mediaserver's memory management routines to trigger the use-after-free condition. Attackers can potentially construct malicious media files or processing requests that force the mediaserver to free memory regions while still maintaining references to them, or alternatively cause memory allocation patterns that result in the reuse of freed memory. When the application attempts to access this memory region after it has been freed, the system behavior becomes unpredictable and can be leveraged to execute arbitrary code within the context of the mediaserver process. The privilege escalation aspect of this vulnerability stems from the fact that the mediaserver typically operates with system-level privileges, meaning successful exploitation could provide attackers with root-level access to the Android device. This aligns with ATT&CK technique T1068 which describes the exploitation of legitimate credentials and privileges to gain elevated access within a system. The vulnerability's exploitation pathway involves understanding the specific memory layout and timing requirements necessary to successfully corrupt memory and redirect execution flow.
The operational impact of CVE-2017-6276 extends beyond simple code execution to encompass complete system compromise when successfully exploited. Mobile device users could be vulnerable to attacks through various vectors including malicious media files received via email, messaging applications, or downloaded content from untrusted sources. The vulnerability affects devices running Android versions that incorporate NVIDIA's media processing stack, making it a widespread concern across multiple device models and manufacturers. Once exploited, the attacker could potentially access all user data, install malicious applications, modify system files, and establish persistent backdoors. The high severity rating reflects the combination of ease of exploitation potential and the significant privileges that can be gained. Organizations and individuals should be particularly concerned about this vulnerability as it represents a sophisticated attack vector that could be automated and deployed at scale. The vulnerability's impact is further amplified by the fact that media processing occurs frequently on mobile devices, creating numerous potential attack opportunities. Security researchers have noted that such use-after-free vulnerabilities often persist in complex multimedia processing systems due to the intricate memory management requirements and the difficulty of ensuring complete bounds checking across all code paths.
Mitigation strategies for CVE-2017-6276 should focus on both immediate patching and defensive measures. The primary solution involves applying the latest security updates from NVIDIA and Android vendors, which typically include memory management fixes and bounds checking improvements. Device manufacturers should implement comprehensive testing of media processing components to identify similar vulnerabilities in their custom implementations. Network administrators should consider implementing content filtering measures to prevent the delivery of potentially malicious media files to affected devices. The Android security model includes several layers of protection that can help mitigate the impact of such vulnerabilities, including SELinux policies and application sandboxing mechanisms. Users should be educated about the risks of downloading content from untrusted sources and should maintain up-to-date security patches. Security monitoring systems should be configured to detect unusual behavior patterns in media processing services that could indicate exploitation attempts. Organizations should conduct vulnerability assessments to identify devices running affected Android versions and prioritize remediation efforts. The remediation process should include not only patching the specific vulnerability but also reviewing the overall security posture of mobile device management systems to prevent similar issues from occurring in other components of the media processing stack.