CVE-2019-25606 Overview
CVE-2019-25606 is a buffer overflow vulnerability affecting Fast AVI MPEG Joiner version 1.2.0812. The vulnerability allows local attackers to crash the application by supplying an oversized payload in the License Name field during the software registration process. When a user pastes approximately 6000 bytes of data into the License Name input field and clicks the Register button, a denial of service condition is triggered, causing the application to crash.
This vulnerability is classified as CWE-787 (Out-of-bounds Write), indicating that the application writes data past the boundaries of allocated memory, leading to application instability and potential exploitation.
Critical Impact
Local attackers can cause a denial of service condition by exploiting improper input validation in the registration dialog, potentially disrupting user workflows and media processing operations.
Affected Products
- Fast AVI MPEG Joiner 1.2.0812
Discovery Timeline
- 2026-03-22 - CVE CVE-2019-25606 published to NVD
- 2026-03-23 - Last updated in NVD database
Technical Details for CVE-2019-25606
Vulnerability Analysis
This buffer overflow vulnerability exists in the license registration functionality of Fast AVI MPEG Joiner. The application fails to properly validate the length of user-supplied input in the License Name field before copying it to a fixed-size buffer. When an attacker provides input exceeding the expected buffer size (approximately 6000 bytes), the application writes beyond the allocated memory region, corrupting adjacent memory structures and ultimately causing the application to crash.
The attack requires local access and user interaction, as the victim must paste the malicious payload into the License Name field and click the Register button. While the immediate impact is a denial of service condition, buffer overflow vulnerabilities of this nature can sometimes be leveraged for more severe attacks such as arbitrary code execution if the memory layout is favorable.
Root Cause
The root cause of this vulnerability is insufficient input validation in the license registration module. The application allocates a fixed-size buffer for the License Name field but fails to enforce proper bounds checking before copying user input. This lack of input sanitization allows attackers to overflow the buffer with excessive data, causing memory corruption.
The CWE-787 classification indicates an out-of-bounds write condition where data is written past the end of the intended buffer, which is a common consequence of missing or inadequate length checks in legacy Windows applications.
Attack Vector
The attack vector is local, requiring the attacker to either have direct access to the system or convince a user to paste malicious content into the registration dialog. The exploitation process involves:
- Creating a text file containing approximately 6000 bytes of arbitrary data
- Copying this content to the clipboard
- Opening the Fast AVI MPEG Joiner application
- Navigating to the registration dialog
- Pasting the oversized payload into the License Name field
- Clicking the Register button to trigger the buffer overflow
The vulnerability requires passive user interaction (UI element activation), making it suitable for social engineering attacks where users are tricked into pasting seemingly legitimate license information.
Detection Methods for CVE-2019-25606
Indicators of Compromise
- Application crash events in Windows Event Viewer associated with Fast AVI MPEG Joiner (fast_avimpegjoiner.exe)
- Unexpected process termination logs for the Fast AVI MPEG Joiner application
- Presence of unusually large text files or clipboard content on the system that could be used as payloads
Detection Strategies
- Monitor for application crash events related to fast_avimpegjoiner.exe with exception codes indicating buffer overflow (access violation)
- Implement endpoint detection rules to alert on repeated crashes of the Fast AVI MPEG Joiner application
- Deploy behavioral analysis to detect attempts to paste large amounts of data into application dialogs
Monitoring Recommendations
- Configure Windows Error Reporting to capture and alert on Fast AVI MPEG Joiner crash dumps
- Implement application allowlisting policies to control which media processing software can run in the environment
- Enable process monitoring to track abnormal terminations of multimedia applications
How to Mitigate CVE-2019-25606
Immediate Actions Required
- Consider removing or replacing Fast AVI MPEG Joiner 1.2.0812 with alternative video joining software that is actively maintained
- Restrict access to the affected application to only trusted users who require media processing capabilities
- Implement application control policies to prevent unauthorized use of the vulnerable software
- Educate users about the risks of pasting unknown content into software registration fields
Patch Information
No official patch has been identified for this vulnerability. The vendor AllokSoft has not released an updated version addressing this buffer overflow issue. Users should consider migrating to alternative software solutions for video file joining operations.
For additional technical details, refer to the Exploit-DB #46929 entry and the VulnCheck Advisory for Fast AVI MPEG Joiner.
Workarounds
- Avoid using the registration functionality in Fast AVI MPEG Joiner if possible
- Run the application in a sandboxed or isolated environment to contain potential crashes
- Implement Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR) at the system level to make exploitation more difficult
- Consider using virtualization to isolate the vulnerable application from critical system resources
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
