CVE-2018-15735 in AntiMalware
Summary
by MITRE
An issue was discovered in STOPzilla AntiMalware 6.5.2.59. The driver file szkg64.sys contains an Arbitrary Write vulnerability due to not validating the output buffer address value from IOCtl 0x8000206F.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 10/07/2023
The vulnerability identified as CVE-2018-15735 represents a critical security flaw within STOPzilla AntiMalware version 6.5.2.59 that exposes the system to potential exploitation through driver-level manipulation. This issue manifests in the szkg64.sys kernel driver component which handles various system operations through Windows I/O control codes. The vulnerability specifically targets the ioctl handler for code 0x8000206F, which processes user-mode requests and subsequently writes data to memory locations specified by the input parameters. The absence of proper validation on the output buffer address creates a dangerous condition where malicious actors can manipulate the memory write operation to target arbitrary locations within the system's address space.
The technical implementation of this vulnerability falls under the category of buffer overflow conditions and memory corruption issues that are commonly classified as CWE-787: Out-of-bounds Write. The flaw occurs when the driver fails to validate the user-supplied buffer address before performing memory write operations, allowing attackers to specify any memory location for data modification. This type of vulnerability is particularly dangerous because it operates at the kernel level where privileges are elevated, potentially enabling attackers to execute arbitrary code with system-level access. The vulnerability exists because the driver does not perform proper bounds checking or address validation on the memory addresses provided through the ioctl interface, creating a direct path for privilege escalation attacks.
The operational impact of this vulnerability extends beyond simple data corruption, as it provides attackers with a mechanism to manipulate critical system components and potentially gain complete control over the affected system. When exploited successfully, the Arbitrary Write vulnerability allows attackers to modify kernel memory structures, inject malicious code into system processes, or manipulate security-related data structures. This capability enables various attack vectors including rootkit installation, privilege escalation, and system compromise. The vulnerability affects systems running the specific version of STOPzilla AntiMalware where the szkg64.sys driver is installed, making it particularly concerning for enterprise environments where multiple systems may be running the vulnerable software. According to ATT&CK framework, this vulnerability maps to T1068: Exploitation for Privilege Escalation and T1059: Command and Scripting Interpreter, as it provides the foundation for executing malicious code with elevated privileges.
Mitigation strategies for CVE-2018-15735 should focus on immediate software updates and system hardening measures. The primary remediation involves upgrading to a patched version of STOPzilla AntiMalware that addresses the buffer validation issue in the szkg64.sys driver component. System administrators should also implement kernel-mode driver verification and monitoring to detect anomalous memory write operations. Additional protective measures include restricting user access to the affected driver interfaces, implementing application whitelisting policies, and conducting regular security assessments of installed security software. Organizations should also consider disabling or removing the vulnerable anti-malware software until proper patches are applied, as the presence of such vulnerabilities in security tools can create dangerous attack surfaces. The vulnerability highlights the importance of proper input validation in kernel-mode drivers and underscores the need for comprehensive security testing of all system components, particularly those operating with elevated privileges.