CVE-2014-7136 in K7Firewall Packet Driver
Summary
by MITRE
Heap-based buffer overflow in the K7FWFilt.sys kernel mode driver (aka K7Firewall Packet Driver) before 14.0.1.16, as used in multiple K7 Computing products, allows local users to execute arbitrary code with kernel privileges via a crafted parameter in a DeviceIoControl API call.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 04/07/2022
The vulnerability identified as CVE-2014-7136 represents a critical heap-based buffer overflow flaw within the K7FWFilt.sys kernel mode driver component of K7 Computing's security suite. This driver serves as the K7Firewall Packet Driver responsible for network traffic filtering and security enforcement within the Windows operating system kernel space. The vulnerability exists in versions prior to 14.0.1.16 and affects multiple products from K7 Computing, making it a widespread concern across their security portfolio.
The technical implementation of this vulnerability stems from inadequate input validation within the kernel mode driver's handling of DeviceIoControl API calls. When a local user crafts a malicious parameter and submits it through the DeviceIoControl interface, the driver fails to properly bounds-check the input data before copying it into a fixed-size heap buffer. This fundamental flaw in memory management creates a condition where user-supplied data can overwrite adjacent memory locations, potentially corrupting critical kernel data structures and execution flow. The heap-based nature of the overflow indicates that the vulnerable buffer is allocated dynamically from the heap memory pool rather than on the stack, which can make exploitation more complex but equally dangerous.
The operational impact of this vulnerability is severe as it provides local attackers with the ability to execute arbitrary code with kernel-level privileges, effectively granting them complete system compromise. This privilege escalation allows attackers to bypass all operating system security mechanisms, access protected memory regions, modify system files, install malware, and establish persistent backdoors. The local execution requirement means that an attacker must already have user-level access to the system, but the privilege escalation to kernel level represents a critical security boundary violation. The vulnerability's presence in multiple K7 Computing products amplifies its impact across various enterprise and consumer environments that rely on their security solutions.
From a cybersecurity framework perspective, this vulnerability maps to CWE-121, which describes heap-based buffer overflow conditions in programming languages like C and C++ where insufficient bounds checking leads to memory corruption. The attack pattern aligns with the ATT&CK technique T1068, known as 'Local Port Forwarding', as the exploitation involves leveraging local system access to gain elevated privileges. Organizations should implement immediate mitigation strategies including applying the vendor-provided patch version 14.0.1.16 or later, which addresses the buffer overflow by implementing proper input validation and bounds checking mechanisms. Additionally, system administrators should monitor for suspicious DeviceIoControl API usage patterns and consider implementing runtime protections such as kernel address space layout randomization and exploit protection features to reduce the likelihood of successful exploitation.
The broader implications of this vulnerability highlight the critical importance of secure kernel driver development practices and regular security assessments of system components that operate with elevated privileges. This flaw demonstrates how even security products can contain exploitable code, emphasizing the need for comprehensive security testing including fuzzing, static code analysis, and dynamic analysis of kernel mode components. Organizations should also consider implementing network segmentation and access controls to limit local user access to systems running vulnerable security software, while maintaining regular patch management processes to address similar vulnerabilities in other security components. The vulnerability serves as a reminder that kernel-level exploits represent the most severe category of security flaws, as they can completely compromise system integrity and confidentiality without requiring network connectivity or complex attack vectors.