CVE-2018-25231: HeidiSQL DOS Vulnerability

CVE-2018-25231 Overview

CVE-2018-25231 is a denial of service vulnerability affecting HeidiSQL version 9.5.0.5196. The vulnerability allows local attackers to crash the application by supplying an excessively long file path in the logging preferences. Specifically, attackers can input a buffer-overflow payload through the SQL log file path field in Preferences > Logging to trigger an application crash.

Critical Impact

Local attackers can cause repeated application crashes, disrupting database management workflows and potentially causing data loss if unsaved changes exist during the crash.

Affected Products

• HeidiSQL 9.5.0.5196

Discovery Timeline

• 2026-03-30 - CVE CVE-2018-25231 published to NVD
• 2026-03-30 - Last updated in NVD database

Technical Details for CVE-2018-25231

Vulnerability Analysis

This denial of service vulnerability stems from improper input validation in HeidiSQL's logging preferences functionality. The application fails to properly validate the length of the file path input when users configure the SQL log file location. When an attacker provides an excessively long string as the file path, the application attempts to process this input without adequate bounds checking, resulting in a buffer overflow condition that causes the application to crash.

The vulnerability is classified under CWE-98, which relates to improper control of filename for Include/Require statement in PHP programs. However, in this context, the core issue is insufficient boundary validation on user-supplied file path input that leads to memory corruption and subsequent application termination.

Root Cause

The root cause of this vulnerability is the lack of proper input length validation in the logging preferences module. When processing the SQL log file path field, HeidiSQL does not enforce maximum length restrictions on the input, allowing attackers to submit arbitrarily long strings. This oversight causes a buffer overflow when the application attempts to store or process the oversized path value, corrupting memory and leading to an unhandled exception that terminates the application.

Attack Vector

The attack requires local access to the HeidiSQL application. An attacker must navigate to Preferences > Logging within the application interface and input an excessively long string (buffer-overflow payload) into the SQL log file path field. Upon submission or when the application attempts to process this path, the buffer overflow is triggered, causing immediate application crash. While this is a local attack vector requiring user interaction with the preferences dialog, it can be exploited to repeatedly disrupt database management operations.

The vulnerability can be triggered by entering a path exceeding the expected buffer size in the logging configuration. The application's failure to validate input length before processing causes memory corruption, resulting in an immediate crash. See the Exploit-DB #45806 entry for technical details on exploitation.

Detection Methods for CVE-2018-25231

Indicators of Compromise

• Unexpected HeidiSQL application crashes, particularly when accessing or modifying logging preferences
• Windows Event Log entries showing application faults in heidisql.exe with exception codes indicating access violations
• Abnormally long file path values in HeidiSQL configuration files or registry entries

Detection Strategies

• Monitor for HeidiSQL application crash events in Windows Event Viewer with exception codes related to buffer overflows or access violations
• Implement application whitelisting and monitoring to detect repeated crash-restart cycles
• Review HeidiSQL configuration files for anomalous path entries exceeding reasonable length limits

Monitoring Recommendations

• Configure endpoint detection to alert on repeated application crashes from heidisql.exe
• Monitor for unusual user activity within HeidiSQL preferences dialogs
• Implement logging for configuration changes in database management tools

How to Mitigate CVE-2018-25231

Immediate Actions Required

• Upgrade HeidiSQL to the latest available version from the HeidiSQL Download Page
• Restrict local access to systems running vulnerable HeidiSQL versions
• Implement application-level input validation through security policies where possible
• Back up any unsaved database work regularly to minimize data loss from potential crashes

Patch Information

Users should update to a newer version of HeidiSQL that addresses this input validation vulnerability. The latest versions are available from the HeidiSQL Official Site. Review the VulnCheck Advisory for HeidiSQL for additional guidance on remediation.

Workarounds

• Restrict access to the HeidiSQL preferences dialog using application control policies
• Run HeidiSQL with limited user privileges to minimize the impact of exploitation
• Avoid allowing untrusted users to access systems with HeidiSQL installed
• Monitor and audit any changes to HeidiSQL logging configuration settings

# Configuration example - Restrict HeidiSQL preferences access via Group Policy
# Note: This is a general mitigation approach, not a fix for the vulnerability
# Create application control policy to monitor HeidiSQL configuration changes
# Ensure only authorized administrators can modify application preferences