CVE-2017-6293 in Android
Summary
by MITRE
In Android before the 2018-05-05 security patch level, NVIDIA Tegra X1 TZ contains a vulnerability in Widevine TA where the software writes data past the end, or before the beginning, of the intended buffer, which may lead to escalation of Privileges. This issue is rated as high. Android: A-69377364. Reference: N-CVE-2017-6293.
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Analysis
by VulDB Data Team • 02/04/2020
The vulnerability identified as CVE-2017-6293 resides within the NVIDIA Tegra X1 TrustZone (TZ) implementation in Android systems, specifically affecting devices running Android versions prior to the 2018-05-05 security patch level. This flaw manifests in the Widevine Trusted Application component, which is responsible for handling digital rights management operations for protected media content. The vulnerability represents a classic buffer overflow condition that occurs when the Widevine TA processes data inputs without proper boundary checks, potentially allowing malicious code to overwrite adjacent memory regions. The issue is particularly concerning as it exists within the TrustZone environment, which is designed to provide a secure execution environment for sensitive operations, making it a critical component for maintaining system integrity and security.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The flaw allows for privilege escalation because the Widevine TA operates with elevated privileges within the TrustZone domain, and improper memory handling within this secure context can enable attackers to gain unauthorized access to system resources. When the TA processes malformed input data, it writes beyond the allocated buffer boundaries, potentially overwriting critical control data such as return addresses, function pointers, or security tokens. This memory corruption can be exploited to execute arbitrary code with the highest system privileges, effectively compromising the entire device's security posture.
The operational impact of CVE-2017-6293 extends beyond simple privilege escalation, as it represents a fundamental breach in the Android security model's layered defense mechanisms. Devices affected by this vulnerability become susceptible to attacks that can bypass the usual security boundaries between user space and kernel space, as well as between different security domains within the TrustZone environment. Attackers could leverage this vulnerability to install persistent backdoors, extract sensitive user data, or manipulate system configurations without detection. The vulnerability's presence in the Widevine TA also means that it affects devices that handle DRM-protected content, potentially impacting media streaming services and digital content distribution platforms that rely on this security infrastructure.
Mitigation strategies for CVE-2017-6293 primarily involve applying the Android security patch released on May 5, 2018, which includes updated versions of the Widevine Trusted Application and related TrustZone components. System administrators should also implement additional protective measures such as enabling automatic security updates, monitoring for suspicious system behavior, and maintaining up-to-date device management policies. The vulnerability demonstrates the critical importance of secure coding practices in trusted execution environments and aligns with ATT&CK technique T1068, which covers local privilege escalation through exploitation of system vulnerabilities. Organizations should conduct comprehensive security assessments of their Android device fleets to identify and remediate affected systems, particularly those handling sensitive information or operating in high-security environments where the risk of exploitation could result in significant data breaches or system compromise.