CVE-2026-30769: TVicPort Privilege Escalation Vulnerability

CVE-2026-30769 Overview

A privilege escalation vulnerability exists in the TVicPort64.sys kernel driver component of EnTech Taiwan TVicPort Product v4.0 (File v5.2.1.0). The vulnerability allows local attackers to escalate privileges by sending specially crafted IOCTL requests with code 0x80002008 to the vulnerable driver. This is classified as an Improper Input Validation vulnerability (CWE-20).

Critical Impact

Local attackers with low privileges can exploit this kernel driver vulnerability to achieve SYSTEM-level access, potentially compromising the entire Windows host.

Affected Products

• EnTech Taiwan TVicPort Product v4.0
• TVicPort64.sys Driver File v5.2.1.0
• Windows systems with the TVicPort driver installed

Discovery Timeline

• 2026-04-29 - CVE CVE-2026-30769 published to NVD
• 2026-04-29 - Last updated in NVD database

Technical Details for CVE-2026-30769

Vulnerability Analysis

The vulnerability resides in the kernel-mode driver TVicPort64.sys, which is part of the TVicPort I/O port access library developed by EnTech Taiwan. The driver fails to properly validate input parameters when processing IOCTL (Input/Output Control) requests, specifically those with control code 0x80002008.

Kernel drivers that expose device interfaces to user-mode applications must carefully validate all input received through IOCTL handlers. When this validation is insufficient or absent, attackers can craft malicious requests that manipulate kernel memory or execute privileged operations, leading to local privilege escalation from a standard user account to SYSTEM privileges.

Root Cause

The root cause is Improper Input Validation (CWE-20) in the IOCTL handler within the TVicPort64.sys driver. The driver does not adequately sanitize or validate the input buffer contents and size parameters passed through DeviceIoControl() calls with IOCTL code 0x80002008. This allows an attacker to supply unexpected or malformed data that the driver processes unsafely, potentially leading to arbitrary memory operations in kernel space.

Attack Vector

The attack requires local access to the target system with low-privilege user credentials. An attacker must:

1. Obtain a handle to the TVicPort device through CreateFile() or similar API calls
2. Craft a malicious IOCTL request with control code 0x80002008
3. Include specially crafted input buffer data designed to exploit the validation weakness
4. Send the request via DeviceIoControl() to trigger the vulnerability

Successful exploitation results in execution of arbitrary code with kernel privileges, effectively granting the attacker complete control over the affected system. Additional technical details and proof-of-concept information may be available in the GitHub Gist resource published by the vulnerability researcher.

Detection Methods for CVE-2026-30769

Indicators of Compromise

• Presence of TVicPort64.sys driver (version 5.2.1.0) in the Windows system32\drivers directory
• Suspicious processes attempting to open handles to \\.\TVicPort device
• Unexpected privilege escalation events from low-privilege user accounts
• Anomalous IOCTL activity targeting the TVicPort driver in kernel trace logs

Detection Strategies

• Monitor for DeviceIoControl() calls targeting TVicPort devices with IOCTL code 0x80002008
• Implement EDR rules to detect processes interacting with vulnerable kernel drivers
• Use driver signing verification to identify potentially tampered driver files
• Deploy SentinelOne Singularity to detect exploitation attempts through behavioral analysis

Monitoring Recommendations

• Enable Windows ETW (Event Tracing for Windows) for kernel driver activity monitoring
• Configure audit policies to log handle creation for device objects
• Monitor for token manipulation and privilege elevation events (Event ID 4672, 4673)
• Implement process integrity level tracking to detect unexpected SYSTEM token acquisition

How to Mitigate CVE-2026-30769

Immediate Actions Required

• Identify all systems with the vulnerable TVicPort64.sys driver installed
• Restrict access to the TVicPort device object using Security Descriptors
• Consider disabling or unloading the driver if not essential for business operations
• Apply application whitelisting to prevent unauthorized access to the driver

Patch Information

At the time of publication, no official vendor patch has been identified. Organizations should monitor the EnTech Taiwan TVicPort product page for security updates. Contact the vendor directly for patch availability and support options.

Workarounds

• Remove or disable the TVicPort64.sys driver if the I/O port access functionality is not required
• Restrict driver device access using Windows Security Descriptors (DACL modifications)
• Implement application control policies to prevent untrusted applications from communicating with the driver
• Use virtualization-based security features where available to isolate kernel driver operations

# Check for vulnerable driver presence
sc query TVicPort
dir C:\Windows\System32\drivers\TVicPort64.sys

# Disable the driver service (requires Administrator privileges)
sc config TVicPort start= disabled
sc stop TVicPort