CVE-2017-9858 in Solar System
Summary
by MITRE
An issue was discovered in SMA Solar Technology products. By sending crafted packets to an inverter and observing the response, active and inactive user accounts can be determined. This aids in further attacks (such as a brute force attack) as one now knows exactly which users exist and which do not.
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Analysis
by VulDB Data Team • 08/05/2024
The vulnerability identified as CVE-2017-9858 affects SMA Solar Technology products, specifically targeting their network communication protocols and user account validation mechanisms. This weakness represents a significant security flaw that exposes the underlying authentication system to information disclosure attacks. The vulnerability stems from insufficient validation of user account status during network communication, allowing attackers to determine whether specific user accounts exist within the system. Such information disclosure creates a critical opening for subsequent exploitation attempts that would otherwise be significantly more difficult to execute.
The technical flaw manifests in the way SMA Solar inverters process network requests and respond to authentication attempts. When crafted network packets are sent to the inverter, the system provides different responses depending on whether the requested user account is active or inactive. This differential response behavior creates a side-channel information leak that attackers can exploit through simple network monitoring and analysis. The vulnerability operates at the application layer of the network stack, specifically affecting the authentication service implementation within the SMA Solar product ecosystem. This type of vulnerability aligns with CWE-200, which addresses information exposure through improper error handling and response differentiation.
The operational impact of this vulnerability extends far beyond simple information disclosure, creating a foundation for more sophisticated attack vectors including brute force authentication attempts. Attackers can leverage the knowledge of existing user accounts to focus their efforts on valid targets rather than wasting resources on non-existent accounts. This significantly reduces the time and computational resources required for successful authentication attacks, making brute force and credential stuffing attacks much more effective. The vulnerability affects the overall security posture of SMA Solar installations, potentially compromising entire solar energy management systems where these inverters are deployed.
Security professionals should implement immediate mitigations to address this vulnerability by configuring proper response handling that does not differentiate between active and inactive account states during authentication attempts. Network segmentation and access controls should be strengthened to limit exposure of affected devices to untrusted networks. Regular security assessments should include testing for similar information disclosure vulnerabilities in network protocols and authentication systems. Organizations should also consider implementing account lockout mechanisms and multi-factor authentication to further protect against exploitation attempts. The vulnerability demonstrates the importance of consistent error handling practices and the need for security controls that prevent side-channel information leakage. This issue aligns with ATT&CK technique T1087.001 for account discovery and T1110.003 for credential stuffing attacks, highlighting the broader threat landscape implications of such information disclosure vulnerabilities in industrial control systems.