CVE-2018-5080 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 0x830020FC.
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Analysis
by VulDB Data Team • 12/19/2019
The vulnerability identified as CVE-2018-5080 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 highest privilege level within the Windows operating system, making it a critical component for system security and stability. The flaw manifests through improper input validation mechanisms within the driver's handling of IOCTL (Input/Output Control) requests, particularly when processing the specific IOCTL code 0x830020FC. This represents a fundamental security weakness that allows malicious actors to manipulate the driver's behavior through crafted input parameters.
The technical exploitation of this vulnerability occurs when a local user crafts malicious input data to be processed by the K7FWHlpr.sys driver during IOCTL 0x830020FC execution. The driver fails to validate the input parameters received from user-mode applications, creating a potential buffer overflow condition or other memory corruption scenarios. This lack of input validation directly correlates to CWE-20, which describes "Improper Input Validation" as a critical weakness in software design. The absence of proper parameter checking allows attackers to send malformed data that can cause unpredictable behavior within the kernel space, potentially leading to system crashes or more severe consequences.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as evidenced by the unspecified other impacts mentioned in the CVE description. A local attacker can trigger a Blue Screen of Death (BSOD) by exploiting this weakness, effectively causing system instability and potential data loss. The kernel-mode nature of the vulnerable driver means that successful exploitation can result in complete system compromise, as the attacker gains access to privileged system resources. This vulnerability particularly aligns with ATT&CK technique T1068, which covers "Local Privilege Escalation," as local users can leverage this flaw to potentially gain elevated privileges. The BSOD condition can also serve as a vector for more sophisticated attacks, as system administrators might be misled into thinking the crash resulted from legitimate hardware or software issues rather than malicious exploitation.
Mitigation strategies for CVE-2018-5080 should focus on immediate software updates from K7 Technologies, as the vendor would need to implement proper input validation mechanisms within the K7FWHlpr.sys driver. System administrators should also implement additional security controls such as disabling unnecessary driver services, monitoring for suspicious IOCTL activity, and maintaining regular system backups. The vulnerability demonstrates the critical importance of kernel-mode driver security validation, as highlighted by industry standards such as the CWE classification system. Organizations should also consider implementing runtime application control measures and monitoring for unusual system behavior that could indicate exploitation attempts. Regular security assessments of third-party security software components are essential to identify similar validation weaknesses that could be exploited by attackers. The vulnerability serves as a reminder that even security software vendors must maintain rigorous input validation practices in their kernel-mode components to prevent exploitation by local users who may have legitimate system access but seek to cause harm or gain unauthorized privileges.