CVE-2025-54465 in WL20 Biometric Attendance System
Summary
by MITRE • 08/13/2025
This vulnerability exists in ZKTeco WL20 due to hard-coded MQTT credentials and endpoints stored in plaintext within the device firmware. An attacker with physical access could exploit this vulnerability by extracting the firmware and analyzing the binary data to retrieve the hard-coded MQTT credentials and endpoints from the targeted device.
Successful exploitation of this vulnerability could allow the attacker to gain unauthorized access to the MQTT broker and manipulate the communications of the targeted device.
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Analysis
by VulDB Data Team • 08/13/2025
The vulnerability identified as CVE-2025-54465 represents a critical security flaw in ZKTeco WL20 devices that stems from poor cryptographic practices and insecure configuration management within the device firmware. This weakness exposes the device to exploitation through physical access attacks that leverage firmware analysis techniques to extract sensitive credentials. The implementation of hard-coded MQTT credentials violates fundamental security principles that require dynamic credential generation and secure storage mechanisms. The presence of plaintext credentials within the firmware creates an inherent risk that persists regardless of network security measures, as these credentials remain accessible to anyone who can extract and analyze the device's binary data.
The technical implementation of this vulnerability manifests through the storage of MQTT broker endpoints and authentication credentials in unencrypted format within the device's firmware image. This approach directly contravenes security best practices outlined in industry standards such as CWE-312 (CWE: Cleartext Storage of Sensitive Information) and CWE-798 (CWE: Use of Hard-coded Credentials). Attackers with physical access can employ standard firmware extraction techniques to obtain the device image, followed by binary analysis to locate and decode the stored credentials. The vulnerability operates at the firmware level, making it particularly dangerous as it bypasses traditional network-based security controls and relies on the assumption that physical security measures are sufficient. This flaw demonstrates a fundamental misunderstanding of security by design principles where sensitive information should be dynamically generated and securely managed rather than embedded within the device's permanent storage.
The operational impact of this vulnerability extends beyond simple credential theft to encompass complete compromise of the device's communication infrastructure. Once attackers obtain the hard-coded MQTT credentials, they can establish unauthorized connections to the MQTT broker and potentially manipulate or intercept all communications between the device and the central management system. This capability enables several attack vectors including man-in-the-middle attacks, data exfiltration, and command injection scenarios that could compromise the entire network infrastructure. The vulnerability affects not only individual device security but also creates potential for broader network compromise through lateral movement attacks that leverage the compromised device as a pivot point. The attack surface expands significantly when considering that multiple devices may share identical or similar hard-coded credentials, creating a single point of failure that could impact entire deployments. This scenario aligns with ATT&CK technique T1071.001 (Application Layer Protocol: Web Protocols) and T1566 (Phishing) when considering the broader implications of compromised device communications.
Effective mitigation strategies for CVE-2025-54465 require immediate firmware updates from ZKTeco to address the hard-coded credential issue through secure credential management practices. Organizations should implement comprehensive device lifecycle management that includes secure firmware deployment and regular security assessments. Physical security measures must be strengthened to prevent unauthorized access to device firmware, including secure storage and access controls for device maintenance. The recommended approach involves implementing dynamic credential generation mechanisms that utilize secure key management systems rather than hard-coded values. Network segmentation and monitoring should be enhanced to detect unauthorized MQTT broker connections and anomalous communication patterns. Security controls should align with NIST SP 800-53 requirements for secure configuration management and continuous monitoring of device communications. Organizations should also consider implementing device authentication mechanisms that do not rely on static credentials, potentially utilizing certificate-based authentication or secure boot processes that prevent unauthorized firmware modifications. The vulnerability underscores the importance of secure development practices and the necessity of conducting thorough security assessments during the device design phase to prevent such fundamental flaws from entering production systems.