CVE-2017-8271 in Android
Summary
by MITRE
Out of bound memory write can happen in the MDSS Rotator driver in all Qualcomm products with Android releases from CAF using the Linux kernel by an unsanitized userspace-controlled parameter.
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Analysis
by VulDB Data Team • 11/06/2019
The vulnerability identified as CVE-2017-8271 represents a critical out-of-bounds memory write flaw within the MDSS Rotator driver component of Qualcomm's Android-based products. This issue specifically affects devices running Android releases from the Code Aurora Forum (CAF) using the Linux kernel, making it prevalent across a wide range of mobile devices that rely on Qualcomm's hardware and software stack. The MDSS Rotator driver serves as a crucial component in Qualcomm's multimedia subsystem, handling image rotation and transformation operations for display purposes, which makes it a prime target for exploitation due to its frequent interaction with user-space applications.
The technical root cause of this vulnerability stems from inadequate input validation within the MDSS Rotator driver where userspace-controlled parameters are not properly sanitized before being processed. When an application or malicious actor provides malformed input parameters to the rotator driver, the kernel component fails to validate the bounds of memory allocations, leading to a situation where memory writes occur beyond the allocated buffer boundaries. This type of vulnerability falls under the Common Weakness Enumeration category CWE-787, which specifically addresses out-of-bounds write conditions. The flaw occurs during the processing of rotation parameters such as width, height, and other transformation values that are passed from user space to kernel space, where the lack of proper boundary checks allows attackers to overwrite adjacent memory locations.
The operational impact of CVE-2017-8271 extends beyond simple data corruption, as it provides potential for arbitrary code execution within the kernel context. Attackers can leverage this vulnerability to escalate privileges from user-level applications to kernel-level operations, effectively gaining complete control over the affected device. The implications are particularly severe given that the vulnerability affects all Qualcomm products utilizing CAF Android releases, meaning that a significant portion of the mobile market could be impacted. This type of privilege escalation aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation', and represents a critical vector for attackers seeking to establish persistent access or perform advanced persistent threat operations on mobile devices. The vulnerability's nature as a kernel-level memory corruption flaw also means that successful exploitation could result in system crashes, data loss, or complete device compromise.
Mitigation strategies for CVE-2017-8271 must address both immediate remediation and long-term security posture improvements. The most effective immediate solution involves applying the security patches provided by Qualcomm and the Android security team, which typically include enhanced input validation and bounds checking within the MDSS Rotator driver. Organizations and device manufacturers should implement comprehensive patch management procedures to ensure timely deployment of these fixes across affected devices. Additionally, runtime protections such as kernel address space layout randomization (KASLR) and stack canaries can provide defense-in-depth measures, though these are not foolproof against sophisticated attacks. The vulnerability also underscores the importance of secure coding practices and thorough input validation, particularly in kernel modules that process user-space data, aligning with the security principles outlined in the OWASP Secure Coding Practices. Device users should be advised to maintain their systems with the latest security updates and avoid installing untrusted applications that might exploit such kernel vulnerabilities.