SRS is a simple, high-efficiency, real-time video server. SRS's `/api/v1/vhosts/vid-<id>?callback=<payload>` endpoint didn't filter the callback function name which led to injecting malicious javascript payloads and executing XSS ( Cross-Site Scripting). This vulnerability is fixed in 5.0.210 and 6.0.121.
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.