CVE-2017-9859 in Solar System
Summary
by MITRE
An issue was discovered in SMA Solar Technology products. The inverters make use of a weak hashing algorithm to encrypt the password for REGISTER requests. This hashing algorithm can be cracked relatively easily. An attacker will likely be able to crack the password using offline crackers. This cracked password can then be used to register at the SMA servers.
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Analysis
by VulDB Data Team • 08/05/2024
The vulnerability identified as CVE-2017-9859 affects SMA Solar Technology products, specifically their inverters that utilize a weak cryptographic hashing algorithm for password encryption in REGISTER requests. This weakness represents a significant security flaw that undermines the authentication mechanisms protecting solar energy systems. The implementation of insufficient cryptographic practices in this context creates an exploitable condition that directly impacts the security posture of connected solar installations. The vulnerability resides in the authentication protocol design where the hashing algorithm employed lacks the computational complexity required to resist modern cryptographic attacks. This flaw allows unauthorized parties to gain legitimate access to SMA server registration services by exploiting the predictable nature of the weak hashing mechanism.
The technical implementation of this vulnerability stems from the use of a hashing algorithm that does not provide adequate security guarantees for password protection. The weak hashing algorithm can be efficiently cracked using offline password cracking tools, which indicates that the cryptographic strength is insufficient for the security requirements of industrial control systems. This type of vulnerability falls under the category of weak cryptographic algorithms as defined by CWE-327, which specifically addresses the use of insecure or broken cryptographic algorithms. The flaw demonstrates a failure to implement proper password hashing practices that would typically involve using strong algorithms with sufficient computational cost such as bcrypt, scrypt, or PBKDF2. The attack vector is particularly concerning because it allows for offline cracking, meaning that attackers can perform their operations without direct network interaction, making detection more difficult and potentially enabling automated attacks against multiple systems.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass potential compromise of solar energy system management and control functions. An attacker who successfully cracks the password gains legitimate registration credentials that can be used to register at SMA servers, potentially enabling them to manipulate system configurations or access sensitive operational data. This situation creates risks for industrial control systems that are part of critical infrastructure, where unauthorized modifications could affect power generation efficiency, safety protocols, or even grid stability. The vulnerability directly impacts the integrity and availability of solar energy systems by allowing malicious actors to establish unauthorized connections to manufacturer services. The attack surface is particularly problematic in environments where solar installations are connected to larger energy management systems, as compromised credentials could enable lateral movement within networked industrial control environments. This weakness also violates fundamental security principles of authentication and access control, potentially exposing organizations to regulatory compliance issues under standards such as NIST SP 800-53 and ISO/IEC 27001.
The mitigation strategies for this vulnerability require immediate implementation of cryptographic improvements to strengthen the password hashing mechanisms within SMA inverters. Organizations should implement strong cryptographic algorithms such as SHA-256 or SHA-3 with appropriate salt values to prevent offline cracking attacks. The solution must address the root cause by replacing the weak hashing algorithm with industry-standard practices that provide sufficient computational complexity to resist modern attack methodologies. System administrators should also consider implementing additional authentication layers including multi-factor authentication to reduce the impact of credential compromise. Regular security assessments and vulnerability scanning should be conducted to identify similar weak cryptographic implementations across industrial control systems. The remediation process must include firmware updates from SMA that address the specific hashing algorithm weakness while maintaining backward compatibility where possible. Organizations should also establish monitoring procedures to detect unauthorized registration attempts and implement network segmentation to limit the potential impact of credential compromise. This vulnerability serves as a reminder of the importance of proper cryptographic implementation in industrial control systems and aligns with ATT&CK technique T1566 which covers credential harvesting through various attack vectors including password cracking and credential reuse attacks.