source: https://www.securityfocus.com/bid/68022/info

Yealink VoIP Phones are prone to an HTTP-response-splitting vulnerability because it fails to properly sanitize user-supplied input.

An attacker may leverage this issue to influence how web content is served, cached, or interpreted. This could aid in various attacks that try to entice client users into a false sense of trust.

Yealink VoIP Phones firmware 28.72.0.2 and hardware 28.2.0.128.0.0.0 are vulnerable; other versions may also be affected. 

GET /servlet?linepage=1&model=%0d%0a[Header]&p=dsskey&q=load