CVE-2014-4910 in xf86-video-intel
Summary
by MITRE
Directory traversal vulnerability in tools/backlight_helper.c in X.Org xf86-video-intel 2.99.911 allows remote attackers to create or overwrite arbitrary files via a .. (dot dot) in the interface name.
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Analysis
by VulDB Data Team • 03/08/2019
The directory traversal vulnerability identified as CVE-2014-4910 resides within the X.Org xf86-video-intel driver version 2.99.911, specifically in the tools/backlight_helper.c component. This flaw represents a critical security weakness that enables remote attackers to manipulate file system operations through improper input validation. The vulnerability manifests when the interface name parameter contains directory traversal sequences using the .. (dot dot) notation, allowing malicious actors to navigate beyond intended directories and target arbitrary files on the system.
The technical implementation of this vulnerability stems from insufficient sanitization of user-supplied input within the backlight helper utility. When the system processes interface names containing traversal sequences, the code fails to properly validate or sanitize these inputs before using them in file system operations. This allows an attacker to craft malicious interface names that, when processed, result in unintended file creation or modification outside the intended scope. The flaw operates at the application level where input validation mechanisms are inadequate, creating a path traversal condition that violates fundamental security principles of least privilege and input sanitization.
The operational impact of this vulnerability extends beyond simple file system manipulation to potentially compromise system integrity and availability. Remote attackers can leverage this weakness to overwrite critical system files, create backdoor access points, or disrupt normal system operations through file corruption. The attack vector is particularly concerning as it operates over network protocols, making exploitation possible without physical access to the target system. This vulnerability affects systems running the affected X.Org driver version and can lead to privilege escalation scenarios when the helper utility executes with elevated permissions. The implications include potential denial of service conditions, data integrity violations, and unauthorized system modification that could persist across reboots.
Security mitigation strategies for CVE-2014-4910 should focus on immediate patching of the affected X.Org xf86-video-intel driver to version 2.99.912 or later, which contains the necessary input validation fixes. System administrators should implement strict input validation procedures for all user-supplied parameters, particularly those used in file system operations. The principle of least privilege should be enforced by ensuring that the backlight helper utility operates with minimal required permissions and that file system access is restricted to only necessary directories. Network segmentation and firewall rules can help limit exposure by restricting access to systems running vulnerable drivers. Additionally, monitoring for suspicious file system activities and implementing automated vulnerability scanning can help detect exploitation attempts. This vulnerability aligns with CWE-22 Directory Traversal and maps to ATT&CK technique T1059 Command and Scripting Interpreter, specifically highlighting the need for proper input validation and secure coding practices in system utilities. Organizations should also consider implementing application whitelisting controls to prevent execution of unauthorized binaries that might exploit similar weaknesses in other system components.