CVE-2018-6522 in AVS
Summary
by MITRE
In nProtect AVS V4.0 4.0.0.38, the driver file (TKRgFtXp.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 0x220408.
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Analysis
by VulDB Data Team • 01/01/2020
The vulnerability identified as CVE-2018-6522 affects nProtect AVS V4.0 version 4.0.0.38 and represents a critical security flaw within the kernel-mode driver component of the antivirus software. This issue stems from insufficient input validation mechanisms within the TKRgFtXp.SYS driver file, which processes IOCTL (Input/Output Control) requests from user-mode applications. The specific IOCTL code 0x220408 exposes the driver to improper handling of user-supplied data, creating a pathway for malicious or unintended input to corrupt system memory or trigger system instability. The vulnerability manifests as a potential blue screen of death (BSOD) during system operation, indicating a severe impact on system availability and stability. This flaw resides within the driver's communication interface between user and kernel space, where proper validation of input parameters should occur before processing sensitive operations. The lack of input sanitization creates an environment where malformed or specially crafted input values can cause the driver to execute invalid memory operations or access unauthorized system resources, ultimately leading to system crashes or unpredictable behavior. This type of vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write vulnerabilities, as the driver fails to properly validate memory boundaries during IOCTL processing. The security implications extend beyond simple denial of service, as the unspecified other impacts could potentially include privilege escalation opportunities or information disclosure vulnerabilities that attackers might exploit to gain deeper system access. From an operational perspective, this vulnerability creates a persistent risk for systems running the affected antivirus version, particularly in enterprise environments where antivirus software is deployed across multiple endpoints. The local nature of the vulnerability means that any user with access to the system can potentially trigger the exploit, making it especially dangerous in multi-user environments or when system privileges are compromised. The vulnerability also demonstrates poor security practices in kernel-mode driver development, specifically the absence of proper input validation and error handling mechanisms that should be fundamental requirements for any system-level software component. The flaw represents a failure in the principle of least privilege and input validation, which are core tenets of secure software development practices. Organizations using nProtect AVS V4.0 should immediately implement mitigations including driver updates from the vendor, system monitoring for suspicious IOCTL activity, and potentially isolating affected systems until patches are deployed. The vulnerability also highlights the importance of proper software testing and code review processes for kernel-mode components, as these elements directly impact system stability and security. Security teams should monitor for exploitation attempts targeting this specific IOCTL code and implement network-based detection measures to identify potential exploitation attempts.
The technical exploitation of CVE-2018-6522 occurs through the manipulation of IOCTL 0x220408 requests sent to the TKRgFtXp.SYS driver, where the driver fails to validate the size, format, or content of input parameters before processing. This validation failure creates a condition where attackers can supply malicious data that causes the driver to perform operations outside of its intended memory boundaries. The vulnerability is classified under the ATT&CK framework as a privilege escalation technique, specifically related to driver manipulation and kernel exploitation. The absence of proper input validation mechanisms allows for potential memory corruption that can be leveraged to execute arbitrary code at kernel level, though the primary impact documented is denial of service. This type of vulnerability is particularly concerning because kernel-mode drivers operate with the highest system privileges, making any flaw in their implementation potentially catastrophic for system security. The vulnerability also aligns with ATT&CK technique T1068, which covers local privilege escalation through kernel exploits, and T1059, which covers command and scripting interpreter usage in kernel contexts. The potential for unspecified other impacts suggests that the vulnerability might be exploitable for more advanced attacks beyond simple BSOD conditions, including privilege elevation or data compromise. Organizations should treat this vulnerability as a high-priority concern, particularly in environments where system stability is critical and where the presence of kernel-mode exploits could provide attackers with persistent access to systems. The vulnerability also demonstrates the need for comprehensive security testing of driver components, including fuzzing and formal verification techniques that can identify input validation gaps before deployment. Security professionals should also consider implementing runtime monitoring for anomalous IOCTL activity patterns that could indicate exploitation attempts targeting this specific vulnerability. The remediation process requires careful attention to ensure that driver updates do not introduce compatibility issues with existing system configurations while addressing the core validation flaws that enable the vulnerability.