CVE-2018-5084 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 0x8300212C.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 12/19/2019
The vulnerability identified as CVE-2018-5084 resides within the K7 AntiVirus 15.1.0306 software suite, specifically targeting the kernel-mode driver component known as K7FWHlpr.sys. This driver operates at the privileged kernel level and interfaces with user-mode applications through Windows I/O Control codes, making it a critical component in the system's security architecture. The flaw manifests when the driver fails to properly validate input parameters received through IOCTL 0x8300212C, creating a potential attack surface that could be exploited by local malicious actors. The vulnerability represents a classic example of inadequate input validation that can lead to system instability and potentially more severe consequences.
The technical implementation of this vulnerability stems from the driver's lack of proper parameter validation for the specific IOCTL code 0x8300212C. When a local user submits crafted input data to this ioctl interface, the driver processes the information without sufficient sanitization or verification of data boundaries. This absence of input validation creates opportunities for buffer overflows, invalid memory access patterns, or other memory corruption issues that can trigger system crashes. The vulnerability aligns with CWE-129, which describes improper validation of input ranges, and CWE-787, which covers out-of-bounds write operations. The driver's failure to validate the size, type, or content of incoming parameters creates a pathway for attackers to manipulate kernel memory structures through carefully crafted malicious input sequences.
The operational impact of this vulnerability extends beyond simple denial of service conditions, though the primary manifestation is a blue screen of death (BSOD) that renders the system unusable until reboot. However, the potential for unspecified other impacts suggests that local attackers might leverage this weakness to escalate privileges or achieve arbitrary code execution within the kernel context. This represents a significant concern as kernel-mode exploits can bypass standard operating system security mechanisms, potentially allowing attackers to gain elevated privileges or access sensitive system resources. The vulnerability's local nature means that exploitation requires physical access or the ability to execute code on the target system, but once exploited, the consequences can be severe enough to compromise the entire system integrity. According to ATT&CK framework, this vulnerability could be categorized under T1068 for locally executed code and potentially T1059 for command execution within the kernel space.
Mitigation strategies for CVE-2018-5084 should prioritize immediate software updates from K7 Technologies, as the vendor has likely released patches addressing the input validation deficiencies in the driver component. System administrators should implement the principle of least privilege, ensuring that only authorized users have access to potentially vulnerable system interfaces. Additionally, monitoring for unusual kernel-mode activity or BSOD events can help detect potential exploitation attempts. Network segmentation and endpoint protection solutions can provide additional layers of defense, though they may not prevent kernel-level exploitation entirely. The vulnerability highlights the importance of proper driver development practices, including comprehensive input validation, memory safety checks, and adherence to secure coding standards. Organizations should also consider implementing runtime application control measures and regular security assessments to identify similar validation flaws in other system components. Regular patch management processes should be enforced to ensure timely deployment of vendor security updates, particularly for security-critical kernel-mode drivers that interface directly with system resources.