CVE-2017-9857 in Solar System
Summary
by MITRE
An issue was discovered in SMA Solar Technology products. The SMAdata2+ communication protocol does not properly use authentication with encryption: it is vulnerable to man in the middle, packet injection, and replay attacks. Any setting change, authentication packet, scouting packet, etc. can be replayed, injected, or used for a man in the middle session. All functionalities available in Sunny Explorer can effectively be done from anywhere within the network as long as an attacker gets the packet setup correctly. This includes the authentication process for all (including hidden) access levels and the changing of settings in accordance with the gained access rights. Furthermore, because the SMAdata2+ communication channel is unencrypted, an attacker capable of understanding the protocol can eavesdrop on communications. NOTE: the vendor's position is that authentication with encryption is not required on an isolated subnetwork. Also, only Sunny Boy TLST-21 and TL-21 and Sunny Tripower TL-10 and TL-30 could potentially be affected
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Analysis
by VulDB Data Team • 06/04/2024
The vulnerability identified as CVE-2017-9857 affects SMA Solar Technology products that utilize the SMAdata2+ communication protocol, representing a critical security flaw in industrial control systems. This issue stems from the protocol's improper implementation of authentication mechanisms combined with inadequate encryption, creating multiple attack vectors that compromise the integrity and confidentiality of solar energy system communications. The vulnerability specifically impacts devices including Sunny Boy TLST-21 and TL-21 inverters and Sunny Tripower TL-10 and TL-30 systems, though the broader implications extend to the entire SMAdata2+ ecosystem. The fundamental flaw lies in the protocol's design where authentication and encryption are not properly integrated, leaving the communication channel exposed to sophisticated attacks that exploit this weakness.
The technical implementation of the SMAdata2+ protocol fails to provide adequate cryptographic protection for communication between solar inverters and monitoring systems. This weakness creates a man-in-the-middle attack surface where attackers can intercept, modify, or replay packets without proper authentication verification. The protocol's vulnerability allows for packet injection attacks where malicious data can be inserted into the communication stream, while replay attacks enable attackers to reuse previously captured packets to perform unauthorized operations. The lack of proper encryption means that all communication can be eavesdropped upon, allowing attackers to understand the protocol structure and potentially reverse engineer the communication patterns to gain deeper access. This architectural flaw directly violates the principle of secure communication in industrial environments, where authentication and encryption should be mandatory components to prevent unauthorized access and data manipulation.
The operational impact of this vulnerability extends far beyond simple data interception, as it provides attackers with comprehensive access to solar system management functions. An attacker capable of exploiting this vulnerability can perform any action available through the Sunny Explorer interface from anywhere within the network, including changing system settings, modifying authentication parameters, and accessing hidden access levels. The vulnerability effectively removes the security boundary that should protect industrial control systems from unauthorized access, allowing attackers to manipulate inverter configurations, potentially causing system instability or safety hazards. This access level includes the ability to modify critical operational parameters that could affect power generation efficiency, system monitoring capabilities, and overall grid integration stability. The attack surface is particularly concerning because it encompasses all functionalities available through the standard communication interface, making it possible for attackers to completely compromise the operational integrity of solar installations.
The security implications of CVE-2017-9857 align with several CWE classifications including CWE-310, which addresses cryptographic issues, and CWE-308, which covers use of a predictable algorithm. The vulnerability also maps to ATT&CK techniques such as T1071.004 for application layer protocol usage and T1566 for phishing attacks that could leverage the compromised communication channels. The vendor's position that authentication with encryption is not required on isolated subnetworks represents a dangerous misconception about security in industrial environments where physical access or network compromise can occur. This vulnerability demonstrates the critical importance of implementing defense-in-depth strategies even within isolated networks, as the assumption that network segmentation alone provides adequate security is fundamentally flawed. Organizations should consider implementing network monitoring solutions and intrusion detection systems to detect anomalous communication patterns that may indicate exploitation attempts.
Mitigation strategies for CVE-2017-9857 should focus on implementing network segmentation with proper access controls, deploying network monitoring solutions to detect suspicious communication patterns, and ensuring that all industrial control system communications are properly encrypted and authenticated. Organizations should also implement network access control measures to limit communication between critical systems and general network segments. The most effective long-term solution involves upgrading affected devices to versions that properly implement authentication and encryption mechanisms, while also establishing network monitoring protocols that can detect the specific packet patterns associated with this vulnerability. Additionally, regular security assessments of industrial control systems should include evaluation of communication protocol implementations to identify similar vulnerabilities that may exist in other components of the industrial network infrastructure.