CVE-2019-25469: Folder Lock 7.7.9 DoS Vulnerability

CVE-2019-25469 Overview

CVE-2019-25469 is a buffer overflow vulnerability affecting Folder Lock version 7.7.9. The vulnerability exists in the serial number registration field and allows local attackers to crash the application by submitting an oversized payload. Specifically, attackers can paste a 6000-byte buffer of arbitrary data into the 'Serial Number and Registration Key' field to trigger a denial of service condition.

Critical Impact

Local attackers can cause application crashes and denial of service by exploiting the buffer overflow in the serial number registration field.

Affected Products

• Folder Lock 7.7.9

Discovery Timeline

• 2026-03-11 - CVE CVE-2019-25469 published to NVD
• 2026-03-12 - Last updated in NVD database

Technical Details for CVE-2019-25469

Vulnerability Analysis

This vulnerability is classified as CWE-787 (Out-of-bounds Write), a memory corruption issue that occurs when the application writes data past the boundaries of allocated memory. The flaw resides in the serial number registration functionality of Folder Lock 7.7.9, where the application fails to properly validate the length of user-supplied input before copying it into a fixed-size buffer.

When a user enters or pastes data into the registration field, the application does not enforce proper bounds checking. This allows an attacker to submit a payload significantly larger than the expected input size, causing the application to write beyond the allocated buffer space and ultimately crash.

Root Cause

The root cause of this vulnerability is improper input validation in the serial number registration handler. The application allocates a fixed-size buffer to store the serial number input but fails to verify that user-supplied data fits within this allocated space. When a 6000-byte payload is submitted, the excessive data overwrites adjacent memory regions, corrupting the application's memory state and causing it to crash.

This type of vulnerability typically stems from the use of unsafe string handling functions that do not perform bounds checking, or from missing length validation before memory copy operations.

Attack Vector

The attack vector is local, meaning an attacker must have local access to the system where Folder Lock is installed. The exploitation requires no special privileges and no user interaction beyond the attacker's own actions. The attack is straightforward to execute:

1. The attacker opens Folder Lock 7.7.9 on the target system
2. The attacker navigates to the registration dialog
3. The attacker pastes approximately 6000 bytes of arbitrary data into the Serial Number and Registration Key field
4. The buffer overflow triggers, causing the application to crash

Technical details and proof-of-concept information can be found in the Exploit-DB #47383 advisory. Additional vulnerability information is available from the VulnCheck Advisory.

Detection Methods for CVE-2019-25469

Indicators of Compromise

• Unexpected crashes of the Folder Lock application, particularly during registration attempts
• Windows Error Reporting (WER) crash dumps indicating access violations or stack buffer overruns in FolderLock.exe
• Application event logs showing repeated unhandled exceptions from Folder Lock

Detection Strategies

• Monitor for abnormal termination of Folder Lock processes using endpoint detection solutions
• Implement application whitelisting to detect unauthorized attempts to interact with Folder Lock registration components
• Use Windows Event Log monitoring to track application crash events associated with Folder Lock

Monitoring Recommendations

• Enable crash dump collection for Folder Lock to capture forensic evidence of exploitation attempts
• Configure SentinelOne endpoint agents to alert on repeated application crashes that may indicate exploitation
• Review system logs for patterns of application instability that could indicate buffer overflow exploitation attempts

How to Mitigate CVE-2019-25469

Immediate Actions Required

• Restrict local access to systems running vulnerable versions of Folder Lock 7.7.9
• Consider temporarily uninstalling or disabling Folder Lock until a patched version is available
• Implement application control policies to prevent unauthorized users from accessing the registration functionality
• Deploy endpoint protection solutions capable of detecting exploitation attempts

Patch Information

At the time of publication, no official patch information is available from the vendor. Users should monitor the official Folder Lock website and security advisories for updates. Consider upgrading to a newer version of Folder Lock if one becomes available that addresses this vulnerability.

For additional technical details, refer to the Exploit-DB #47383 entry and the VulnCheck Advisory.

Workarounds

• Restrict access to the Folder Lock application to trusted users only
• Implement least-privilege access controls on systems where Folder Lock is installed
• Consider using alternative file encryption solutions until a patch is available
• Deploy endpoint protection solutions to monitor for and alert on exploitation attempts