CVE-2018-5087 in K7
Summary
by MITRE
In K7 AntiVirus 15.1.0306, the driver file (K7FWHlpr.sys) allows local users to cause a denial of service (BSOD) or possibly have unspecified other impact because of not validating input values from IOCtl 0x83002100.
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Analysis
by VulDB Data Team • 12/19/2019
The vulnerability identified as CVE-2018-5087 resides within K7 AntiVirus version 15.1.0306, specifically in the kernel-mode driver component K7FWHlpr.sys. This driver interface exposes a critical security flaw through its handling of input validation for the IOCTL 0x83002100 control code, creating a pathway for privilege escalation and system instability. The flaw represents a classic example of improper input validation that can be exploited by local attackers to manipulate the driver's behavior in ways that were not anticipated by the software developers.
The technical implementation of this vulnerability demonstrates a failure in the driver's request processing logic where it does not adequately validate the parameters provided during IOCTL 0x83002100 operations. This type of validation failure maps directly to CWE-20, which encompasses improper input validation issues in software systems. When malicious input is passed to the driver through this specific IOCTL command, the system experiences unpredictable behavior that can result in a Blue Screen of Death (BSOD) or potentially more severe consequences. The lack of parameter sanitization creates opportunities for buffer overflows, memory corruption, or other exploitable conditions that could be leveraged to disrupt normal system operations.
From an operational perspective, this vulnerability presents significant risks to system availability and stability. Local users with minimal privileges can trigger system crashes that effectively create a denial of service condition, making the affected system unreliable for its intended purposes. The potential for unspecified other impacts suggests that beyond simple system instability, this vulnerability could potentially enable more sophisticated attacks such as privilege escalation or information disclosure. The vulnerability's nature as a kernel-mode issue means that successful exploitation could potentially compromise the entire system, as the driver operates with elevated privileges and direct access to system resources. This aligns with ATT&CK technique T1068 which covers 'Local Privilege Escalation' through kernel exploits.
The mitigation strategies for this vulnerability should focus on immediate driver updates from K7 Technologies to address the input validation deficiencies. System administrators should implement comprehensive monitoring for unusual IOCTL activity patterns that might indicate exploitation attempts. Additionally, the principle of least privilege should be enforced through proper access controls and user account management to limit potential exploitation scope. Organizations should also consider implementing runtime application control measures and kernel-mode protection mechanisms to detect and prevent unauthorized driver interactions. The vulnerability serves as a reminder of the critical importance of proper input validation in kernel-mode drivers, particularly when dealing with IOCTL interfaces that provide direct system access pathways.