CVE-2020-14513: Wibu CodeMeter DOS Vulnerability

CVE-2020-14513 Overview

CVE-2020-14513 is an Improper Input Validation vulnerability affecting Wibu CodeMeter, a widely deployed software protection and licensing solution used in industrial control systems (ICS) and enterprise environments. The vulnerability exists in how CodeMeter processes license files, where unverified length fields in a specially crafted license file can cause the application and any software relying on it to crash.

Critical Impact

A remote attacker can cause a denial of service condition by sending a maliciously crafted license file, potentially disrupting critical industrial systems and software licensing operations across affected environments.

Affected Products

• Wibu CodeMeter (All versions prior to 6.81)
• Software applications utilizing CodeMeter for license management
• Industrial control systems relying on CodeMeter-protected software

Discovery Timeline

• 2020-09-16 - CVE-2020-14513 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2020-14513

Vulnerability Analysis

This vulnerability falls under CWE-20 (Improper Input Validation), a class of weaknesses where software fails to properly validate user-supplied input before processing. In the context of CodeMeter, the license file parser does not adequately verify length fields contained within license files before using them in memory operations.

When CodeMeter processes a license file, it reads various fields including length indicators that define the size of subsequent data blocks. Without proper bounds checking on these length values, an attacker can craft a license file with malicious length fields that cause the parser to read beyond allocated memory boundaries, access invalid memory regions, or trigger other undefined behavior resulting in an application crash.

The impact is significant given that CodeMeter is often deployed as a critical dependency for industrial software licensing. A crash in CodeMeter can cascade to all software relying on it for license verification, potentially affecting operational technology (OT) environments.

Root Cause

The root cause of this vulnerability is the absence of proper validation for length fields within the license file parsing routine. The CodeMeter application trusts the length values specified in incoming license files without verifying they fall within acceptable bounds or match the actual available data. This creates a condition where malformed input can trigger memory access violations or buffer overreads.

Attack Vector

This vulnerability is exploitable over the network with low attack complexity and requires no authentication or user interaction. An attacker can exploit this vulnerability by:

1. Crafting a specially formatted license file containing malicious length field values
2. Delivering the malicious license file to a target system running a vulnerable version of CodeMeter
3. When the CodeMeter service attempts to process the crafted file, the unverified length fields cause improper memory access
4. The resulting memory corruption leads to a crash of the CodeMeter service and any dependent applications

The attack does not require prior authentication, making it accessible to any network-adjacent attacker who can reach the CodeMeter service.

Detection Methods for CVE-2020-14513

Indicators of Compromise

• Unexpected crashes of the CodeMeter runtime service (CodeMeter.exe or codemeter daemon)
• Application event logs showing CodeMeter service termination with memory access violations
• Presence of unusual or malformed license files (.WibuCmLIF or similar extensions) in license directories
• Multiple restart attempts of CodeMeter-dependent applications following license validation failures

Detection Strategies

• Monitor CodeMeter service processes for unexpected terminations or crash events
• Implement file integrity monitoring on license file directories to detect introduction of suspicious files
• Deploy network intrusion detection rules to identify malformed license file transmissions
• Analyze system crash dumps for patterns consistent with memory access violations in CodeMeter components
• Review application logs for repeated license validation failures preceding service crashes

Monitoring Recommendations

• Enable verbose logging for CodeMeter service operations to capture license file processing activities
• Configure alerts for CodeMeter service availability drops or repeated restart cycles
• Implement endpoint detection monitoring for anomalous behavior in processes interacting with license files
• Establish baseline metrics for CodeMeter service stability and alert on deviations

How to Mitigate CVE-2020-14513

Immediate Actions Required

• Upgrade all CodeMeter installations to version 6.81 or later immediately
• Restrict network access to CodeMeter services to trusted hosts and networks only
• Review and remove any suspicious or unknown license files from license directories
• Implement network segmentation to isolate systems running CodeMeter in industrial environments
• Monitor for exploitation attempts while patches are being deployed

Patch Information

Wibu Systems has addressed this vulnerability in CodeMeter version 6.81 and later releases. Organizations should obtain the latest version of CodeMeter from Wibu Systems and deploy it across all affected systems. The patch implements proper validation of length fields during license file processing to prevent crafted files from causing crashes.

For additional details and patch guidance, refer to the CISA ICS Advisory ICSA-20-203-01.

Workarounds

• Implement strict network access controls to limit which hosts can communicate with CodeMeter services
• Configure firewall rules to block untrusted sources from reaching CodeMeter network ports
• Enable application whitelisting to prevent execution of unauthorized license file processing tools
• Temporarily disable remote license file processing capabilities if business operations permit
• Isolate critical systems running CodeMeter from untrusted network segments until patching is complete

# Example: Restrict CodeMeter network access via firewall rules
# Block external access to CodeMeter default port (22350)
iptables -A INPUT -p tcp --dport 22350 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 22350 -j DROP

# Verify CodeMeter version
codemeter --version
# Ensure output shows version 6.81 or higher