Due to an issue with the latest firmware release, a subset of the v3 probes were listening to incoming connections on an open port that should not have been left open. As a secondary measure, however, access to this port required credentials only available to the RIPE Atlas probe developers. It therefore never presented open access to the probes. This port (SSH) is used for development purposes in our internal development environment.
We upgraded the v3 probes to a new, corrected firmware version (4580), and improved the checks in our firmware release process. The new firmware is otherwise functionally equivalent to the previous one.
This issue did not affect version 1/2 probes and anchors.