CVE-2021-36799 in ETS5
Summary
by MITRE • 07/19/2021
KNX ETS5 uses the hard-coded password ETS5Password, with a salt value of Ivan Medvedev.
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Analysis
by VulDB Data Team • 08/04/2024
The vulnerability identified as CVE-2021-36799 represents a critical security flaw in KNX ETS5 software, which is widely used for configuring and managing KNX building automation systems. This issue stems from the implementation of hard-coded credentials within the software, specifically utilizing the password ETS5Password combined with a salt value of Ivan Medvedev. The presence of such hard-coded authentication mechanisms creates a fundamental weakness in the system's security architecture, as these credentials are embedded within the application code and cannot be changed by administrators. This vulnerability affects the integrity and confidentiality of building automation networks that rely on KNX ETS5 for configuration management, potentially exposing critical infrastructure to unauthorized access and manipulation.
The technical flaw manifests through the use of hardcoded cryptographic parameters that violate fundamental security principles outlined in the CWE (Common Weakness Enumeration) catalog under CWE-798, which specifically addresses the use of hard-coded credentials. The salt value Ivan Medvedev represents a predictable and well-known value that significantly weakens the cryptographic protection mechanism. This weakness is particularly concerning because it provides attackers with a known credential pair that can be used to authenticate to the system without requiring knowledge of legitimate user credentials. The vulnerability exists at the application level and affects the authentication process within the KNX ETS5 configuration environment, making it a direct threat to the security posture of building automation systems that depend on this software.
From an operational perspective, this vulnerability creates significant risk for organizations managing building automation systems, as it allows unauthorized individuals to gain administrative access to KNX network configurations. The impact extends beyond simple credential theft, as attackers with access can modify network parameters, alter device configurations, and potentially disrupt critical building operations such as heating, ventilation, lighting, and security systems. The attack surface is particularly concerning because KNX systems are commonly deployed in critical infrastructure environments including hospitals, government buildings, and industrial facilities where unauthorized access could result in operational disruption, safety hazards, or data compromise. This vulnerability aligns with ATT&CK technique T1078.004 which covers legitimate credentials, and represents a clear path for privilege escalation within building automation environments.
Mitigation strategies for this vulnerability should focus on immediate remediation through software updates provided by the vendor, as well as implementation of network-level security controls. Organizations should conduct comprehensive assessments of their KNX ETS5 installations to identify systems using the affected software and ensure all instances are updated to versions that address this hard-coded credential issue. Network segmentation and access controls should be implemented to limit exposure of KNX networks to unauthorized systems. Additionally, administrators should consider implementing multi-factor authentication mechanisms where possible, and establish monitoring procedures to detect unauthorized access attempts. The vulnerability demonstrates the importance of following security best practices such as those outlined in NIST SP 800-53 and ISO/IEC 27001, which emphasize the need for proper credential management and the elimination of hard-coded authentication values in security-critical applications. Organizations should also consider conducting regular security assessments of their building automation systems to identify and remediate similar vulnerabilities that may exist in other components of their infrastructure.