CVE-2018-15733 in AntiMalware
Summary
by MITRE
An issue was discovered in STOPzilla AntiMalware 6.5.2.59. The driver file szkg64.sys contains a NULL Pointer Dereference vulnerability due to not validating the size of the output buffer value from IOCtl 0x80002028.
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Analysis
by VulDB Data Team • 10/07/2023
The vulnerability identified as CVE-2018-15733 represents a critical NULL pointer dereference flaw within the STOPzilla AntiMalware 6.5.2.59 software suite, specifically within the szkg64.sys kernel driver component. This issue arises from inadequate input validation mechanisms that fail to properly assess the size of output buffer parameters when processing IOCTL (Input/Output Control) requests. The affected IOCTL code 0x80002028 demonstrates a fundamental flaw in the driver's security architecture, where the system does not validate whether the supplied buffer size parameter meets the expected minimum requirements before proceeding with memory operations. This particular vulnerability resides in the kernel-mode driver layer, making it particularly dangerous as it operates with elevated privileges and can potentially be exploited by malicious actors to compromise system integrity.
The technical implementation of this vulnerability stems from the driver's failure to validate the buffer size parameter associated with the specified IOCTL request. When the szkg64.sys driver receives an IOCTL request with code 0x80002028, it attempts to process the request without first verifying that the output buffer provided by the user-mode application contains sufficient space for the expected data. This lack of validation creates a condition where a NULL pointer dereference can occur, leading to potential system crashes or, more critically, arbitrary code execution. The vulnerability aligns with CWE-476 which specifically addresses NULL pointer dereference issues in software implementations. The flaw essentially allows attackers to craft malicious IOCTL requests that deliberately provide invalid buffer size parameters, causing the driver to attempt to access memory locations that have not been properly allocated or initialized.
The operational impact of this vulnerability extends beyond simple system instability, as it creates potential attack vectors for privilege escalation and system compromise. Since the szkg64.sys driver operates at kernel level within the Windows operating system, successful exploitation could enable attackers to execute arbitrary code with the highest system privileges. This presents a significant risk to endpoint security, particularly in enterprise environments where anti-malware solutions are deployed across multiple systems. The vulnerability can be exploited through various attack vectors including malicious software installation, drive-by downloads, or exploitation of other vulnerabilities that allow privilege escalation. According to ATT&CK framework, this vulnerability maps to T1055 (Process Injection) and T1068 (Local Privilege Escalation) techniques, as it provides a pathway for attackers to gain elevated system access through kernel-level manipulation. The impact is particularly severe as it affects a security product designed to protect against malware, creating a potential attack surface that undermines the very security measures intended to defend against threats.
Mitigation strategies for CVE-2018-15733 should prioritize immediate patching of the STOPzilla AntiMalware software to version 6.5.2.60 or later, which contains the necessary fixes to validate buffer size parameters during IOCTL processing. System administrators should also implement additional security controls including kernel-mode driver verification, application whitelisting policies, and monitoring for suspicious IOCTL activity. The vulnerability highlights the importance of proper input validation and buffer management in kernel-mode drivers, which should follow secure coding practices such as those outlined in the CERT Secure Coding Standards. Organizations should also consider implementing behavioral monitoring solutions that can detect anomalous IOCTL request patterns and potentially indicate exploitation attempts. Regular security assessments of endpoint protection software are essential to identify similar vulnerabilities in other security tools that may be running with kernel-level privileges. The remediation process should include comprehensive testing to ensure that the patched version does not introduce compatibility issues with existing security policies or system configurations while maintaining the integrity of the endpoint protection framework.