AppDynamics has fixed a security issue introduced in Web Server Agent v126.96.36.199.
This issue was identified in all Web Server Agent versions between v188.8.131.52 and v184.108.40.206.
In v220.127.116.11, support for Virtual Hosts in Apache was added to the Web Server Agent. However, SSL connection requests between the Agent and Controller would fail when SSL was enabled within the Agent.
This issue did not impact any Web Servers Agents connected without SSL.
Customers with Web Server Agents that require SSL should connect to the controller and update to 18.104.22.168, which contains the resolution for this issue.
If upgrading to 22.214.171.124 is not viable, pre-4.2.3 agent versions that are 4.2.x should be sufficient.