CVE-2019-25336: SpotAuditor Buffer Overflow Vulnerability

CVE-2019-25336 Overview

CVE-2019-25336 is a local buffer overflow vulnerability affecting SpotAuditor 5.3.2, specifically within the Base64 Encrypted Password tool. This stack-based buffer overflow (CWE-121) allows attackers to execute arbitrary code by crafting a malicious payload. By generating a specially crafted Base64 encoded input, an attacker can trigger a Structured Exception Handler (SEH) overwrite, ultimately enabling shellcode execution on the vulnerable system.

Critical Impact

Successful exploitation of this vulnerability allows attackers to achieve arbitrary code execution with the privileges of the SpotAuditor application, potentially leading to full system compromise through SEH overwrite techniques.

Affected Products

• SpotAuditor version 5.3.2
• Base64 Encrypted Password tool component
• NSauditor Network Security Auditor Suite (containing SpotAuditor)

Discovery Timeline

• 2026-02-12 - CVE CVE-2019-25336 published to NVD
• 2026-02-12 - Last updated in NVD database

Technical Details for CVE-2019-25336

Vulnerability Analysis

This vulnerability is classified as CWE-121 (Stack-based Buffer Overflow), a memory corruption flaw that occurs when data is written beyond the bounds of a stack-allocated buffer. The Base64 Encrypted Password tool in SpotAuditor 5.3.2 fails to properly validate the length of user-supplied input before copying it into a fixed-size buffer on the stack. This lack of boundary checking creates an exploitable condition where excessive input data can overwrite critical stack structures, including the Structured Exception Handler (SEH) chain.

The local attack vector requires user interaction, as an attacker must craft a malicious payload and convince a user to process it through the vulnerable tool. When the overflow occurs, the attacker can precisely control the SEH overwrite to redirect execution flow to attacker-controlled shellcode placed in memory.

Root Cause

The root cause of this vulnerability lies in insufficient input validation within the Base64 decryption routine. The application allocates a fixed-size buffer on the stack to store decoded password data but does not verify that the incoming Base64 encoded string will fit within this allocation after decoding. This classic programming error enables an attacker to supply oversized input that exceeds buffer boundaries, corrupting adjacent stack memory including saved return addresses and exception handler pointers.

Attack Vector

Exploitation of CVE-2019-25336 follows a classic SEH overwrite pattern. The attacker constructs a payload consisting of padding bytes to fill the buffer and reach the SEH chain, followed by carefully crafted addresses that hijack exception handling. When the overflow triggers an exception (either organically or forced by the attacker), Windows exception handling walks the SEH chain, eventually reaching the attacker-controlled handler pointer. This redirects execution to a POP-POP-RET gadget sequence, which ultimately transfers control to shellcode positioned earlier in the payload.

The vulnerability requires local access and user interaction, as the malicious payload must be processed through the Base64 Encrypted Password tool interface. Technical details and proof-of-concept exploits demonstrating this technique are available through the Exploit-DB #47719 and Exploit-DB #47759 references.

Detection Methods for CVE-2019-25336

Indicators of Compromise

• Abnormal memory access patterns or crashes within SpotAuditor.exe processes
• Process memory anomalies indicating shellcode injection or SEH chain manipulation
• Unexpected child process spawning from SpotAuditor application
• Windows Event Log entries showing application exceptions with unusual handler addresses

Detection Strategies

• Monitor for exploitation attempts by tracking exception handling anomalies in SpotAuditor processes
• Deploy endpoint detection rules to identify SEH overwrite patterns characteristic of buffer overflow exploitation
• Implement application whitelisting to prevent unauthorized code execution from exploited applications
• Use memory protection solutions that detect stack corruption and shellcode execution attempts

Monitoring Recommendations

• Enable Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR) to increase exploitation difficulty
• Configure endpoint protection to monitor SpotAuditor process behavior for signs of memory corruption
• Audit usage of the Base64 Encrypted Password tool feature and restrict access where possible
• Implement application crash analysis to identify potential exploitation attempts

How to Mitigate CVE-2019-25336

Immediate Actions Required

• Discontinue use of SpotAuditor version 5.3.2 until a patched version is available
• Remove or disable the Base64 Encrypted Password tool if not required for operations
• Restrict local access to systems running vulnerable SpotAuditor installations
• Implement application sandboxing to contain potential exploitation impact

Patch Information

No vendor patch information is currently available in the CVE data. Users should monitor the NSauditor website for security updates and newer versions that address this vulnerability. Organizations should consider alternative password auditing tools that do not contain known buffer overflow vulnerabilities. For additional technical details, refer to the VulnCheck Advisory.

Workarounds

• Enable Windows exploit protection features including DEP and ASLR for SpotAuditor processes
• Restrict access to SpotAuditor to trusted administrators only
• Avoid processing untrusted Base64 encoded password data through the vulnerable tool
• Consider implementing application isolation through virtualization or containerization

# Enable DEP for SpotAuditor process (Windows PowerShell)
Set-ProcessMitigation -Name "SpotAuditor.exe" -Enable DEP
Set-ProcessMitigation -Name "SpotAuditor.exe" -Enable ForceRelocateImages