CVE-2017-17803 in Vir.IT eXplorer Lite
Summary
by MITRE
In TG Soft Vir.IT eXplorer Lite 8.5.65, the driver file (VIRAGTLT.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 0x82736068, a different vulnerability than CVE-2017-17475.
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Analysis
by VulDB Data Team • 12/16/2019
The vulnerability identified as CVE-2017-17803 affects TG Soft Vir.IT eXplorer Lite version 8.5.65, specifically targeting the VIRAGTLT.SYS kernel driver component. This represents a critical security flaw that demonstrates poor input validation practices within device driver software, creating potential pathways for unauthorized system compromise. The vulnerability manifests through improper handling of input parameters submitted via IOCTL (Input/Output Control) command 0x82736068, which is a standard mechanism used by Windows kernel drivers to communicate with user-mode applications. The driver's failure to properly validate incoming data creates a condition where malicious or malformed input can trigger unexpected behavior within the kernel space, potentially leading to system instability or complete system failure.
The technical nature of this vulnerability places it within the category of improper input validation flaws, which aligns with CWE-20 - Improper Input Validation. This weakness occurs when software does not properly validate or sanitize input data before processing it, allowing attackers to submit malicious payloads that can manipulate system behavior. The vulnerability specifically affects the kernel driver's handling of IOCTL requests, where the driver fails to implement proper parameter checking mechanisms before executing operations. When a local user submits crafted input to the IOCTL 0x82736068 command, the driver processes this data without adequate validation, potentially causing memory corruption or execution flow disruption. This type of vulnerability can be exploited to trigger a Blue Screen of Death (BSOD) by corrupting kernel memory structures or by causing privilege escalation attempts that force system shutdown.
From an operational perspective, this vulnerability presents significant risk to systems running the affected software, as it allows local users to potentially cause system crashes or service interruptions that could impact business operations. The potential for unspecified other impacts suggests that beyond simple denial of service, the vulnerability may enable more sophisticated attacks including privilege escalation or information disclosure. The fact that this is a local vulnerability means that an attacker must already have access to the system to exploit it, but this limitation does not reduce the overall risk since local access often implies a compromised system or insider threat. The vulnerability's classification as a kernel-level issue means that any exploitation could potentially result in complete system compromise, as kernel-level code operates with the highest privileges and can directly manipulate system resources.
The attack surface for this vulnerability extends beyond simple system crashes, as it demonstrates the broader principle that device drivers represent critical attack vectors in operating system security models. According to ATT&CK framework, this vulnerability relates to T1059 - Command and Scripting Interpreter and T1068 - Exploitation for Privilege Escalation, as the improper input handling could potentially be leveraged to gain elevated privileges within the system. The vulnerability also connects to T1489 - Service Stop, as the BSOD condition represents a form of service disruption that can be used to deny legitimate system access. Mitigation strategies should focus on input validation improvements, including implementing proper parameter checking, bounds validation, and error handling within the driver code. System administrators should ensure that the affected software is updated to versions that address this vulnerability, while also implementing monitoring for unusual IOCTL activity patterns that might indicate exploitation attempts. Additionally, the vulnerability highlights the importance of driver code reviews and security testing, particularly for kernel-mode components that handle user input, as these represent some of the most critical security boundaries in operating system architecture.