CVE-2018-5958 in Zillya!
Summary
by MITRE
In Zillya! Antivirus 3.0.2230.0, the driver file (zef.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 0x9C402424.
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Analysis
by VulDB Data Team • 12/26/2019
The vulnerability identified as CVE-2018-5958 resides within Zillya! Antivirus version 3.0.2230.0 and specifically targets the zef.sys kernel driver component. This represents a critical security flaw that exposes the antivirus software to potential exploitation through improper input validation mechanisms. The issue manifests when the driver processes IOCTL (Input/Output Control) requests, particularly the specific control code 0x9C402424, which governs communication between user-mode applications and the kernel-mode driver. The absence of proper validation for input parameters creates a pathway for malicious actors to manipulate driver behavior and potentially compromise system stability.
The technical flaw stems from inadequate parameter validation within the kernel driver's handling of IOCTL requests. When user applications submit requests to the zef.sys driver using the specified IOCTL code, the driver fails to properly validate the input data structures before processing them. This validation gap allows attackers to craft malformed input values that can trigger unexpected behavior within the driver's execution context. According to CWE classification, this vulnerability maps to CWE-129, which describes "Improper Validation of Array Index," and CWE-707, which covers "Improper Neutralization of Input During Web Page Generation." The lack of input sanitization creates a direct pathway for privilege escalation and system instability.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable more severe consequences within the target system. Local users who can execute code with sufficient privileges can leverage this flaw to trigger Blue Screen of Death (BSOD) conditions, effectively rendering the system unusable until reboot. Beyond immediate system disruption, the vulnerability may allow for more insidious attacks that could lead to privilege escalation or information disclosure. The unspecified other impacts referenced in the CVE description suggest that the vulnerability might enable additional attack vectors that could be exploited to compromise system integrity or confidentiality. This aligns with ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation," and T1490, covering "Inhibit System Recovery," where the BSOD condition effectively prevents normal system operation.
Mitigation strategies for CVE-2018-5958 should focus on immediate patch deployment from the vendor, as the vulnerability exists within the kernel driver component where traditional user-mode protections are insufficient. Organizations should implement network segmentation to limit local user access to systems running affected antivirus software, while also monitoring for unusual BSOD patterns or system instability that might indicate exploitation attempts. The vulnerability's nature as a kernel-level flaw makes traditional endpoint protection measures ineffective, requiring system administrators to apply vendor patches immediately and consider system hardening measures that reduce the attack surface. Additionally, implementing monitoring solutions that can detect anomalous IOCTL activity patterns may help identify exploitation attempts before they cause system disruption. Security teams should also consider temporarily disabling the affected antivirus driver component during patch deployment to minimize system downtime while maintaining security coverage through alternative protective measures.