CVE-2017-9861

CVE-2017-9861 describes a critical vulnerability in the SIP implementation of specific SMA Solar Technology products, including Sunny Boy TLST-21 and TL-21, and Sunny Tripower TL-10 and TL-30. The flaw stems from the lack of proper authentication with encryption, making affected devices susceptible to replay, packet injection, and man-in-the-middle attacks. With a CVSS score of 9.8 (CRITICAL), an unauthenticated attacker on the local area network can exploit this to crash devices, disrupt communication with SMA servers, or extract sensitive information like passwords due to unencrypted SIP communications. While the vendor asserts encryption is unnecessary on isolated subnetworks, the vulnerability has a high FAUCET Risk Score of 77/100. There is no known active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or KEV entry, but it has garnered some community discussion and media coverage, including concerns about potential power grid impacts.