Wordfence tries to download the latest firewall rule set from its update server. The request uses PHP cURL. The server aborts the request after the configured timeout because it fails to establish a connection or complete the TLS handshake. The abort generates cURL error 28 and Wordfence reports the failure.
The timeout occurs when outbound traffic is blocked, DNS does not resolve, network path is slow, or PHP/cURL settings limit the connection time. High server load or outdated libraries also cause the request to exceed the timeout limit.