The non Hayes version was called Time Independent Escape Sequence or TIES, but there were multiple versions of these problems, with the later attacks documented in CVE-1999-1228 where you did have to have some form of echo/ping/icmp to work on a client device.

The earlier issue with finger was due to manufactures having brain dead firmware and using AT commands for voice features in the 14.4 modems etc... I can't seem to find it in the usenet archives that are still around, or at least with current search engine tuning.