An issue in Yealink T21P_E2 Phone 52.84.0.15 allows a remote normal privileged attacker to execute arbitrary code via a crafted request the ping function of the diagnostic component.

Yealink T21P_E2 Phone 52.84.0.15 is vulnerable to Directory Traversal. A remote normal privileged attacker can read arbitrary files via a crafted request result read function of the diagnostic component.

Multiple cross-site scripting (XSS) vulnerabilities in Local Phone book and Blacklist form in Yealink VOIP Phones allow remote authenticated users to inject arbitrary web script or HTML via the user field to cgi-bin/ConfigManApp.com.