CVE-2020-37213: TextCrawler Pro DOS Vulnerability

CVE-2020-37213 Overview

CVE-2020-37213 is a denial of service vulnerability affecting TextCrawler Pro 3.1.1, a text search and replace utility developed by Digital Volcano. The vulnerability allows attackers to crash the application by sending an oversized buffer in the license key field. By generating a 6000-byte payload and pasting it into the activation field, an attacker can trigger an application crash, disrupting normal operations.

Critical Impact

Local attackers can crash TextCrawler Pro 3.1.1 by exploiting improper buffer handling in the license key activation field, causing denial of service conditions.

Affected Products

• TextCrawler Pro 3.1.1

Discovery Timeline

• 2026-02-11 - CVE CVE-2020-37213 published to NVD
• 2026-02-12 - Last updated in NVD database

Technical Details for CVE-2020-37213

Vulnerability Analysis

This vulnerability is classified under CWE-120 (Buffer Copy without Checking Size of Input), commonly known as a Classic Buffer Overflow. The application fails to properly validate the size of input provided to the license key activation field before copying it into a fixed-size buffer. When an oversized input (approximately 6000 bytes) is provided, it exceeds the allocated buffer space, leading to memory corruption and subsequent application crash.

The local attack vector requires user interaction, as the attacker must either have direct access to the system or convince a user to paste the malicious payload into the activation field. While the impact is limited to application availability (no confidentiality or integrity breach), it can disrupt workflows for users who depend on TextCrawler Pro for text processing tasks.

Root Cause

The root cause of this vulnerability lies in improper input validation within the license key activation mechanism. The application allocates a fixed-size buffer for the license key input but does not enforce length restrictions before copying user-supplied data. This classic buffer overflow condition (CWE-120) allows attackers to provide input exceeding the expected buffer size, corrupting adjacent memory and causing the application to crash.

Attack Vector

The attack is executed locally and requires user interaction. An attacker must generate a payload of approximately 6000 bytes and input it into the license activation field. This can be accomplished through direct access to the application or through social engineering techniques that convince a user to paste the malicious string. The attack does not require authentication or elevated privileges, making it accessible to any user with access to the application.

The exploitation mechanism is straightforward: the oversized input overwhelms the buffer allocated for the license key, causing memory corruption that results in an unhandled exception and application termination. Technical details regarding the exploit are available via the Exploit-DB #47862 entry.

Detection Methods for CVE-2020-37213

Indicators of Compromise

• Unexpected TextCrawler Pro application crashes, particularly during license activation attempts
• Windows Event Log entries indicating application faults in the TextCrawler Pro process
• Presence of unusually large clipboard contents (6000+ bytes) when the application crashes
• User reports of application instability when entering license keys

Detection Strategies

• Monitor Windows Application Event Logs for crash events related to TextCrawler Pro processes
• Implement endpoint detection rules to identify buffer overflow patterns in desktop applications
• Deploy SentinelOne Singularity to detect and alert on abnormal application termination events
• Review clipboard activity logs for unusually large text content being pasted into applications

Monitoring Recommendations

• Configure endpoint monitoring to track TextCrawler Pro process stability and crash frequency
• Establish baseline application behavior metrics to detect anomalous termination patterns
• Enable enhanced logging on systems where TextCrawler Pro is deployed for business-critical operations
• Utilize SentinelOne's behavioral AI to identify potential denial of service attack patterns

How to Mitigate CVE-2020-37213

Immediate Actions Required

• Evaluate the criticality of TextCrawler Pro in your environment and consider temporary removal if not essential
• Restrict access to the license activation functionality to trusted administrators only
• Monitor affected systems for signs of exploitation attempts
• Contact Digital Volcano for information regarding patched versions

Patch Information

As of the last NVD update, no specific vendor patch has been documented for this vulnerability. Organizations should check the Digital Volcano Homepage for the latest version of TextCrawler Pro and any security updates. The VulnCheck Advisory for TextCrawler may contain additional remediation guidance.

Workarounds

• Restrict access to the TextCrawler Pro license activation dialog to prevent untrusted input
• Implement application whitelisting policies to control which users can launch and modify TextCrawler Pro settings
• Consider using alternative text search and replace utilities until a patch is available
• Educate users about the risks of pasting untrusted content into application license fields

# Example: Restrict application execution using Windows AppLocker
# Create a rule to limit TextCrawler Pro access to administrators only
New-AppLockerPolicy -RuleType Publisher -User "DOMAIN\Administrators" -Path "C:\Program Files\TextCrawler Pro\TextCrawler.exe"