The application fails to prevent users from connecting to it over unencrypted connections. An attacker able to modify a legitimate user's network traffic could bypass the application's use of SSL/TLS encryption and use the application as a platform for attacks against its users.
https://www.solarwinds.com/trust-center/security-advisories/CVE-2021-35246
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-35246