smrsh(8) on FreeBSD
The text 6b496c75db94, as FreeBSD 2.2.9-RELEASE, FreeBSD 2.2.8-RELEASE, FreeBSD 2.2.7-RELEASE, FreeBSD 2.2.6-RELEASE, FreeBSD 2.2.5-RELEASE, FreeBSD 2.2.2-RELEASE, FreeBSD 2.1.7.1-RELEASE, FreeBSD 2.1.7-RELEASE shipped it.
restricted shell for sendmail