Connections to external data sources, like e-mail autoconfiguration, were not terminated in case they hit a timeout, instead those connections were logged

Connections to external data sources, like e-mail autoconfiguration, were not terminated in case they hit a timeout, instead those connections were logged. Some connections use user-controlled endpoints, which could be malicious and attempt to keep the connection open for an extended period of time. As a result users were able to trigger large amount of egress network connections, possibly exhausting network pool resources and lock up legitimate requests. A new mechanism has been introduced to cancel external connections that might access user-controlled endpoints. No publicly available exploits are known.