An issue was discovered in SMA Solar Technology products. The SIP implementation does not properly use authentication with encryption: it is vulnerable to replay attacks, packet injection attacks, and man in the middle attacks. An attacker is able to successfully use SIP to communicate with the device from anywhere within the LAN. An attacker may use this to crash the device, stop it from communicating with the SMA servers, exploit known SIP vulnerabilities, or find sensitive information from the SIP communications. Furthermore, because the SIP communication channel is unencrypted, an attacker capable of understanding the protocol can eavesdrop on communications. For example, passwords can be extracted. 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