CVE-2019-25551: Sandboxie DOS Vulnerability

CVE-2019-25551 Overview

CVE-2019-25551 is a denial of service vulnerability affecting Sandboxie version 5.30. The vulnerability allows local attackers to crash the application by supplying an excessively long string in the Program Alerts configuration field. Specifically, attackers can paste a buffer of 5000 characters into the "Select or enter a program" field during program alert configuration to trigger an application crash.

Critical Impact

Local attackers can cause a denial of service condition in Sandboxie 5.30, disrupting the sandboxed application environment and potentially affecting system security by disabling sandbox protections.

Affected Products

• Sandboxie-plus Sandboxie version 5.30 (Classic edition)
• Systems running Sandboxie Classic with Program Alerts feature enabled
• Windows environments utilizing Sandboxie for application isolation

Discovery Timeline

• 2026-03-21 - CVE-2019-25551 published to NVD
• 2026-03-23 - Last updated in NVD database

Technical Details for CVE-2019-25551

Vulnerability Analysis

This vulnerability is classified under CWE-1282 (Assumed-Immutable Data is Stored in Writable Memory) and CWE-1284 (Improper Validation of Specified Quantity in Input). The root issue lies in the application's failure to properly validate the length of user-supplied input within the Program Alerts configuration interface.

When a user configures program alerts in Sandboxie 5.30, the application accepts input in the "Select or enter a program" field without adequate boundary checks. This allows attackers with local access to supply an input string of approximately 5000 characters, overwhelming the application's input buffer and causing an unhandled exception that results in an application crash.

The local attack vector means an attacker must have some level of access to the system to exploit this vulnerability. While this limits the attack surface compared to remote vulnerabilities, it still poses a significant risk in shared computing environments or scenarios where an attacker has limited user access and seeks to disable security controls.

Root Cause

The vulnerability stems from improper input validation in the Program Alerts configuration component. Sandboxie 5.30 fails to enforce appropriate length restrictions on user-supplied strings before processing them. The application assumes that input provided through the configuration interface will be within expected bounds, but does not validate this assumption before attempting to store or process the data.

Attack Vector

The attack is performed locally through the Sandboxie user interface. An attacker with access to the Sandboxie configuration can navigate to the Program Alerts settings and paste an excessively long string (approximately 5000 characters) into the program selection field. This triggers a buffer overflow condition that crashes the application.

The attack does not require elevated privileges and can be executed by any user with access to the Sandboxie configuration interface. Upon successful exploitation, the Sandboxie application terminates unexpectedly, potentially leaving sandboxed applications unprotected.

For detailed technical information about the exploitation technique, refer to the Exploit-DB #46860 entry and the VulnCheck Advisory.

Detection Methods for CVE-2019-25551

Indicators of Compromise

• Unexpected termination of the Sandboxie service or application (SbieSvc.exe, SbieCtrl.exe)
• Application crash logs indicating buffer overflow or access violation in the Program Alerts component
• Event log entries showing abnormal Sandboxie process termination without user-initiated shutdown

Detection Strategies

• Monitor for repeated Sandboxie application crashes using Windows Event Viewer or endpoint detection solutions
• Implement application monitoring to detect abnormally long strings being passed to Sandboxie configuration interfaces
• Deploy endpoint detection rules that alert on Sandboxie process crashes accompanied by memory access violations

Monitoring Recommendations

• Enable Windows Error Reporting to capture crash dump files from Sandboxie processes for forensic analysis
• Configure SentinelOne endpoint agents to monitor for suspicious application terminations in security-critical software
• Review Sandboxie configuration files for anomalous entries that may indicate exploitation attempts

How to Mitigate CVE-2019-25551

Immediate Actions Required

• Upgrade Sandboxie to a version newer than 5.30 that includes proper input validation
• Restrict local access to the Sandboxie configuration interface to authorized administrators only
• Consider deploying Sandboxie-Plus, the actively maintained open-source continuation of the Sandboxie project
• Monitor for application crashes and investigate any unexpected Sandboxie terminations

Patch Information

Users should upgrade to a patched version of Sandboxie that addresses the input validation vulnerability. The Sandboxie Official Website provides information on available versions. Organizations using Sandboxie Classic should evaluate migration to Sandboxie-Plus, which receives active security updates from the open-source community.

Workarounds

• Restrict access to the Sandboxie Control Panel to trusted administrators only
• Implement application control policies to prevent unauthorized modification of Sandboxie settings
• Deploy monitoring solutions to detect and alert on Sandboxie application crashes
• Consider using alternative sandboxing solutions until the vulnerability can be patched

# Restrict access to Sandboxie configuration (Windows)
# Limit user permissions on Sandboxie installation directory
icacls "C:\Program Files\Sandboxie" /inheritance:r /grant:r "SYSTEM:(OI)(CI)F" /grant:r "Administrators:(OI)(CI)F"