CVE-2019-25563: Uvnc Pchelpwarev2 DOS Vulnerability

CVE-2019-25563 Overview

CVE-2019-25563 is a denial of service vulnerability affecting PCHelpWareV2 version 1.0.0.5, a remote support application developed by UVNC. The vulnerability allows local attackers to crash the application by supplying a malformed image file. Specifically, attackers can trigger the vulnerability through the Create SC (Service Configuration) feature by selecting a crafted BMP file with an oversized buffer, causing the application to crash and become unavailable.

Critical Impact

Local attackers can cause application crashes and denial of service by exploiting improper image file handling in the Create SC feature, disrupting remote support operations.

Affected Products

• UVNC PCHelpWareV2 version 1.0.0.5

Discovery Timeline

• 2026-03-21 - CVE CVE-2019-25563 published to NVD
• 2026-03-24 - Last updated in NVD database

Technical Details for CVE-2019-25563

Vulnerability Analysis

This denial of service vulnerability stems from improper handling of image files within PCHelpWareV2's Create SC functionality. When processing BMP image files, the application fails to properly validate the file's buffer size before processing. An attacker can craft a malicious BMP file with an oversized buffer that exceeds the expected boundaries, causing the application to crash when the file is loaded through the Create SC feature.

The vulnerability is classified under CWE-226 (Sensitive Information in Resource Not Removed Before Reuse), though the primary impact manifests as an application crash rather than information disclosure. The local attack vector means an attacker must have local access to the system running PCHelpWareV2 to exploit this vulnerability. No user interaction is required once the malicious file is positioned, and no privileges are needed to trigger the crash.

Root Cause

The root cause of CVE-2019-25563 lies in insufficient input validation when processing BMP image files. The application does not properly verify the buffer size specified in the BMP file header against the actual data or expected constraints. When an attacker supplies a BMP file with an oversized buffer declaration, the application attempts to process more data than it can safely handle, resulting in a crash condition.

Attack Vector

The attack is executed locally through the following sequence:

1. An attacker creates a specially crafted BMP file containing an oversized buffer declaration in its header
2. The attacker accesses the PCHelpWareV2 application on the target system
3. Using the Create SC (Service Configuration) feature, the attacker selects the malicious BMP file
4. The application attempts to process the crafted image without proper validation
5. The oversized buffer causes the application to crash, resulting in denial of service

Technical details and a proof-of-concept are available through the Exploit-DB #46708 entry.

Detection Methods for CVE-2019-25563

Indicators of Compromise

• Unexpected PCHelpWareV2 application crashes, particularly when using the Create SC feature
• Presence of unusual or recently created BMP files in directories accessible by the application
• System event logs showing application termination errors for PCHelpWareV2 processes
• Multiple application restart attempts in a short time period

Detection Strategies

• Monitor for repeated PCHelpWareV2 process crashes using Windows Event Log monitoring
• Implement file integrity monitoring for directories where the application processes image files
• Deploy endpoint detection rules that alert on application crashes following BMP file access
• Use SentinelOne behavioral AI to detect anomalous application termination patterns

Monitoring Recommendations

• Configure application crash logging and alerting for PCHelpWareV2 processes
• Monitor for suspicious BMP file creation or modification in user-accessible directories
• Implement centralized logging to correlate crash events across multiple endpoints
• Review Windows Application Event Log (Event ID 1000, 1001) for application fault events related to PCHelpWareV2

How to Mitigate CVE-2019-25563

Immediate Actions Required

• Restrict local access to systems running PCHelpWareV2 to trusted users only
• Implement application whitelisting to prevent unauthorized file uploads
• Monitor for and investigate any unexpected application crashes
• Consider upgrading to a newer version of PCHelpWareV2 if available from UVNC
• Evaluate alternative remote support solutions if no patch is available

Patch Information

No official patch information is available in the current CVE data. Users should check the UVNC Official Website for potential security updates or newer versions of PCHelpWareV2. The VulnCheck Advisory on PCHelpWare may provide additional guidance on remediation options.

Workarounds

• Restrict local access to the PCHelpWareV2 application to trusted administrators only
• Implement file type validation at the operating system level to inspect BMP files before they can be accessed by the application
• Disable or restrict access to the Create SC feature if it is not required for operations
• Deploy endpoint protection solutions like SentinelOne to detect and prevent exploitation attempts
• Consider running PCHelpWareV2 in an isolated environment or sandbox to limit the impact of crashes