CVE-2014-8956 in K7AV Sentry Device Driver
Summary
by MITRE
Stack-based buffer overflow in the K7Sentry.sys kernel mode driver (aka K7AV Sentry Device Driver) before 12.8.0.119, as used in multiple K7 Computing products, allows local users to execute arbitrary code with kernel privileges via unspecified vectors.
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Analysis
by VulDB Data Team • 04/07/2022
The vulnerability identified as CVE-2014-8956 represents a critical stack-based buffer overflow flaw within the K7Sentry.sys kernel mode driver component of K7 Computing's security suite. This driver serves as the kernel-mode device driver for the K7AV Sentry protection system, which is integrated into various K7 Computing security products including antivirus and endpoint protection solutions. The vulnerability affects versions prior to 12.8.0.119 and exposes a fundamental flaw in how the driver handles input data within kernel space, creating a pathway for privilege escalation attacks that can compromise the entire system.
The technical implementation of this vulnerability stems from improper bounds checking within the kernel-mode driver code, specifically in the K7Sentry.sys module. When legitimate input data is processed by the driver, insufficient validation occurs to ensure that the data fits within allocated stack buffers, allowing attackers to overwrite adjacent memory locations. This type of flaw falls under CWE-121 Stack-based Buffer Overflow, which is classified as a critical weakness in software security architecture. The vulnerability manifests when local users exploit this condition through unspecified vectors that likely involve crafted input to the driver interface, potentially through direct system calls or device IOCTL operations that the driver handles in kernel context.
The operational impact of this vulnerability is severe and directly enables local privilege escalation attacks that can result in complete system compromise. Since the vulnerability operates within kernel mode, successful exploitation allows attackers to execute arbitrary code with the highest system privileges, effectively bypassing all user-mode security controls including application whitelisting, user access controls, and standard operating system security mechanisms. This privilege escalation capability aligns with ATT&CK technique T1068, which describes the exploitation of legitimate credentials and system privileges to gain elevated access. The attack surface is particularly concerning because it requires only local user access to the system, making it accessible through common attack vectors such as social engineering, compromised user accounts, or other initial compromise methods that lead to local execution.
The exploitation of this vulnerability creates a persistent threat vector that can be leveraged for advanced persistent threats, data exfiltration, system reconnaissance, and further lateral movement within compromised networks. Attackers can utilize the elevated privileges to modify system files, install rootkits, disable security services, and establish backdoor access that remains undetected by standard security monitoring tools. Organizations using affected K7 Computing products face significant risk of unauthorized system access and potential data breaches. The vulnerability's classification as a kernel-mode buffer overflow makes it particularly dangerous because it can be used to bypass modern security mitigations such as DEP, ASLR, and stack canaries that typically protect against similar user-mode exploits. Security professionals should note that this vulnerability demonstrates the critical importance of kernel-mode driver security validation and proper input sanitization in system-level software components. The recommended mitigation strategy involves immediate patching of affected systems to version 12.8.0.119 or later, along with comprehensive security audits of kernel-mode drivers in the environment. Additionally, implementing runtime protection mechanisms and monitoring for suspicious kernel-mode activities can help detect exploitation attempts, while maintaining network segmentation and access controls provides defense-in-depth against potential lateral movement following successful exploitation.