Security News > 2023 > October > Messaging Service Wiretap Discovered through Expired TLS Cert
2023-10-27 11:01
The suspected man-in-the-middle attack was identified when the administrator of jabber.
Ru, the largest Russian XMPP service, received a notification that one of the servers' certificates had expired.
Ru found no expired certificates on the server, as explained in a blog post by ValdikSS, a pseudonymous anti-censorship researcher based in Russia who collaborated on the investigation.
The expired certificate was instead discovered on a single port being used by the service to establish an encrypted Transport Layer Security connection with users.
Before it had expired, it would have allowed someone to decrypt the traffic being exchanged over the service.