CVE-2017-5696 in Graphics Driver
Summary
by MITRE
Untrusted search path in Intel Graphics Driver 15.40.x.x, 15.45.x.x, and 21.20.x.x allows unprivileged user to elevate privileges via local access.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 12/24/2019
The vulnerability identified as CVE-2017-5696 represents a critical privilege escalation flaw within Intel Graphics Drivers version 15.40.x.x, 15.45.x.x, and 21.20.x.x, where an untrusted search path issue enables local attackers to elevate their privileges without requiring administrative credentials. This vulnerability falls under the category of path traversal and privilege escalation attacks, specifically manifesting as a weakness in how the graphics driver handles file system paths during execution. The flaw stems from improper handling of the dynamic link library (dll) search order, where the driver fails to properly validate or sanitize the paths used to locate required libraries. When a user runs a program that relies on the affected graphics driver, the system searches through a predefined list of directories to locate necessary components, but due to insufficient path validation, malicious actors can manipulate this process to load attacker-controlled code instead of legitimate system libraries.
The technical implementation of this vulnerability exploits the Windows search path mechanism, where the operating system follows a specific order to locate executable files and dynamic link libraries. In affected Intel graphics drivers, the search path includes directories that are writable by unprivileged users, creating an opportunity for attackers to place malicious dll files in these locations. When the graphics driver attempts to load required libraries, it will first search these user-accessible directories before checking system protected locations, allowing attackers to inject malicious code that executes with elevated privileges. This behavior aligns with CWE-426, which describes the weakness of untrusted search paths, and represents a classic example of how improper privilege management can lead to system compromise. The vulnerability is particularly dangerous because it requires no special permissions to exploit, as local access is sufficient to manipulate the search path and achieve privilege escalation.
The operational impact of CVE-2017-5696 extends beyond simple local privilege escalation, as it can serve as a foundational attack vector for more sophisticated compromise techniques. An attacker who gains initial access to a system through other means can leverage this vulnerability to elevate their privileges to system level, enabling them to modify critical system files, install backdoors, or access sensitive data that would otherwise be protected. The vulnerability affects a wide range of Intel graphics drivers used in both desktop and enterprise environments, making it a significant concern for organizations that rely on Intel graphics hardware. This flaw also demonstrates the broader challenge of maintaining secure software supply chains, as vulnerabilities in graphics drivers can provide attackers with persistent access to systems. The attack surface is particularly concerning in enterprise environments where multiple users share systems and where the graphics driver is frequently used by various applications, creating numerous potential entry points for exploitation.
Mitigation strategies for CVE-2017-5696 should focus on both immediate remediation and long-term defensive measures to prevent similar vulnerabilities from emerging. The most direct solution involves updating to Intel graphics drivers that have been patched to address the untrusted search path issue, which typically includes implementing proper path validation and ensuring that system-critical libraries are loaded from secure, protected locations. Organizations should also implement application whitelisting policies that restrict which programs can execute on systems, thereby limiting the potential impact of path manipulation attacks. Additionally, system administrators should conduct regular security audits to identify and remediate similar vulnerabilities in other software components, as the underlying issue of improper path handling is common across many software systems. The vulnerability also highlights the importance of following secure coding practices such as those outlined in the MITRE ATT&CK framework, particularly in the context of privilege escalation techniques that leverage environmental weaknesses. Network segmentation and user access controls should be implemented to limit the potential damage from successful exploitation, while monitoring systems should be configured to detect unusual patterns of dll loading that might indicate exploitation attempts.