CVE-2019-25340: SpotAuditor Base64 DoS Vulnerability

CVE-2019-25340 Overview

CVE-2019-25340 is a denial of service vulnerability affecting SpotAuditor version 5.3.2. The vulnerability exists in the Base64 decryption feature of the application, allowing attackers to crash the application by supplying an oversized buffer. Specifically, attackers can generate a malformed input file containing 2000 repeated characters that, when pasted into the Base64 Encrypted Password field, triggers an application crash due to a stack-based buffer overflow (CWE-121).

Critical Impact

Local attackers can reliably crash the SpotAuditor application through oversized input in the Base64 decryption field, causing denial of service and potential data loss for users actively working with the tool.

Affected Products

• SpotAuditor 5.3.2
• NSAuditor SpotAuditor Base64 decryption component

Discovery Timeline

• 2026-02-12 - CVE CVE-2019-25340 published to NVD
• 2026-02-12 - Last updated in NVD database

Technical Details for CVE-2019-25340

Vulnerability Analysis

This vulnerability is classified as a stack-based buffer overflow (CWE-121). The root cause lies in insufficient input validation within the Base64 decryption component of SpotAuditor. When processing input data in the Base64 Encrypted Password field, the application fails to properly validate the length of user-supplied data before copying it to a fixed-size stack buffer. This allows a local attacker to provide an input exceeding the expected buffer size, leading to memory corruption and subsequent application crash.

The attack requires local access and user interaction, as the malicious input must be pasted into the application's interface. While the impact is limited to availability (denial of service), the stack-based nature of this overflow could potentially be leveraged for more severe attacks depending on the execution environment and available protections.

Root Cause

The vulnerability stems from improper bounds checking in the Base64 decryption routine. The application allocates a fixed-size buffer on the stack to hold decoded data but does not verify that incoming encoded data, when decoded, will fit within this allocated space. When an attacker supplies approximately 2000 or more repeated characters, the resulting data overflows the stack buffer, corrupting adjacent memory and causing the application to crash.

Attack Vector

The attack vector is local, requiring an attacker to craft a malicious input file or string containing an oversized payload (approximately 2000 repeated characters). The attacker then must convince a user to paste this content into the Base64 Encrypted Password field, or potentially load a malicious project file. Upon processing, the application attempts to decode the oversized input, triggering the buffer overflow and crashing the application.

The vulnerability does not require elevated privileges to exploit, but does require user interaction to paste the malicious input. Additional technical details and proof-of-concept information can be found in the Exploit-DB #47719 advisory and the VulnCheck Denial of Service Advisory.

Detection Methods for CVE-2019-25340

Indicators of Compromise

• Unexpected SpotAuditor application crashes when processing Base64 input
• Error logs indicating stack corruption or access violations in SpotAuditor processes
• Presence of unusually large text files or clipboard content containing repetitive character patterns near the workstation

Detection Strategies

• Monitor for repeated SpotAuditor process terminations that may indicate exploitation attempts
• Implement endpoint detection rules to flag anomalous application crashes with stack-based exceptions
• Review Windows Event Logs for application fault events referencing SpotAuditor executables

Monitoring Recommendations

• Enable application crash monitoring for SpotAuditor processes on endpoints where the software is deployed
• Configure SentinelOne agents to alert on repeated application faults that could indicate active exploitation
• Establish baseline behavior for SpotAuditor usage to identify anomalous patterns

How to Mitigate CVE-2019-25340

Immediate Actions Required

• Verify installed SpotAuditor versions and identify systems running vulnerable version 5.3.2
• Restrict usage of the Base64 decryption feature until a patch is available or the software is updated
• Educate users to avoid pasting untrusted or unknown content into SpotAuditor input fields
• Consider removing or replacing SpotAuditor if it is not critical to operations

Patch Information

No specific vendor patch information is available in the current CVE data. Users should check the NSAuditor website for potential updates or newer versions of SpotAuditor that may address this vulnerability. Monitor security advisories from the vendor for remediation guidance.

Workarounds

• Avoid using the Base64 Encrypted Password decryption feature with untrusted input until a patch is available
• Implement application whitelisting to prevent unauthorized or modified versions of SpotAuditor from executing
• Restrict access to SpotAuditor to trusted administrators who understand the risk of processing unknown input
• Consider running SpotAuditor in an isolated environment or virtual machine to contain potential crashes

# Configuration example: Restrict SpotAuditor execution via Windows AppLocker
# Create a rule to limit SpotAuditor to specific trusted users
# Run in PowerShell as Administrator

# Export current AppLocker policy
Get-AppLockerPolicy -Effective -Xml > C:\Temp\AppLockerPolicy.xml

# Review and modify policy to restrict SpotAuditor.exe execution
# Add path rule for SpotAuditor installation directory