CVE-2018-25211: Allok Video Splitter Buffer Overflow Flaw

CVE-2018-25211 Overview

CVE-2018-25211 is a buffer overflow vulnerability affecting Allok Video Splitter version 3.1.1217. This vulnerability allows local attackers to cause a denial of service condition or potentially execute arbitrary code by supplying an oversized string in the License Name field during software registration. The exploitation requires user interaction, as the overflow is triggered when a user pastes a malicious payload exceeding 780 bytes into the License Name registration field and clicks the Register button.

Critical Impact

Successful exploitation enables attackers to crash the application or execute arbitrary code with the privileges of the running user, potentially leading to system compromise.

Affected Products

• Allok Video Splitter version 3.1.1217

Discovery Timeline

• 2026-03-26 - CVE-2018-25211 published to NVD
• 2026-03-26 - Last updated in NVD database

Technical Details for CVE-2018-25211

Vulnerability Analysis

This vulnerability is classified as CWE-787 (Out-of-bounds Write), a memory corruption flaw where the application writes data beyond the boundaries of an allocated memory buffer. The Allok Video Splitter application fails to properly validate the length of user-supplied input in the License Name field during the registration process.

When a user enters registration information, the application copies the License Name string into a fixed-size buffer without adequate bounds checking. By providing an input string exceeding 780 bytes, an attacker can overwrite adjacent memory regions, potentially corrupting the stack and gaining control over program execution flow.

The local attack vector requires an attacker to either have direct access to the target system or convince a user to paste the malicious payload. The vulnerability requires user interaction to trigger, as the victim must click the Register button after inputting the oversized string.

Root Cause

The root cause of this vulnerability is improper input validation and the use of unsafe memory operations when handling user-supplied data in the License Name registration field. The application allocates a fixed-size buffer for the license name but does not enforce length restrictions on the input, allowing attackers to supply data that exceeds the buffer capacity and overwrites adjacent memory.

Attack Vector

The attack is carried out locally and requires user interaction. An attacker crafts a malicious string payload larger than 780 bytes, typically containing shellcode or return address overwrite sequences. This payload is then pasted into the License Name field of the registration dialog. When the user clicks the Register button, the application attempts to process the input, triggering the buffer overflow and potentially allowing arbitrary code execution.

The exploitation technique follows a classic stack-based buffer overflow pattern where the attacker carefully constructs the payload to:

1. Fill the legitimate buffer space
2. Overwrite saved return addresses or exception handlers
3. Redirect execution to attacker-controlled shellcode

For detailed technical analysis and proof-of-concept information, refer to the Exploit-DB #44605 entry and the VulnCheck Advisory on Buffer Overflow.

Detection Methods for CVE-2018-25211

Indicators of Compromise

• Presence of Allok Video Splitter version 3.1.1217 installed on systems
• Application crashes or unexpected termination of VideoSplitter.exe process
• Suspicious clipboard activity containing unusually long strings (780+ bytes)
• Unexpected child processes spawned from the Video Splitter application

Detection Strategies

• Monitor for crashes or abnormal behavior in Allok Video Splitter processes
• Implement endpoint detection rules to identify exploitation attempts against legacy multimedia software
• Use application whitelisting to prevent unauthorized or legacy software from executing
• Deploy memory protection mechanisms (DEP, ASLR) which may mitigate exploitation success

Monitoring Recommendations

• Audit installed software inventory for vulnerable Allok Video Splitter versions
• Monitor Windows Event Logs for application crash events related to Video Splitter
• Implement process monitoring to detect anomalous behavior following Video Splitter execution
• Review system for presence of unknown executables or suspicious process trees originating from multimedia applications

How to Mitigate CVE-2018-25211

Immediate Actions Required

• Uninstall Allok Video Splitter version 3.1.1217 from affected systems immediately
• Replace with alternative video splitting software from vendors with active security support
• Implement application control policies to prevent execution of vulnerable software
• Ensure endpoint protection solutions are enabled with exploit prevention capabilities

Patch Information

No vendor patch is currently available for this vulnerability. The software vendor AllokSoft does not appear to be actively maintaining this product. Organizations should consider discontinuing use of this software and migrating to actively supported alternatives. For reference, the vendor's website can be found at AllokSoft Official Page.

Workarounds

• Remove or disable Allok Video Splitter from production systems entirely
• If removal is not immediately possible, restrict user access to the registration functionality
• Deploy endpoint protection with memory protection features (DEP, ASLR enforcement)
• Educate users not to paste untrusted content into application registration fields
• Implement network segmentation to limit potential lateral movement from compromised systems

# Remove Allok Video Splitter from Windows systems
# Run as Administrator

# Uninstall via Windows Package Manager (if registered)
wmic product where name="Allok Video Splitter" call uninstall /nointeractive

# Alternative: Manual removal - check common installation paths
del /f /q "C:\Program Files\Allok Video Splitter\*.*"
rmdir /s /q "C:\Program Files\Allok Video Splitter"

# Remove registry entries
reg delete "HKLM\SOFTWARE\Allok Software" /f