Debian: DSA-4377-1 Critical: Rssh Arbitrary Command Execution Threat

The ESnet security team discovered a vulnerability in rssh, a restricted
shell that allows users to perform only scp, sftp, cvs, svnserve
(Subversion), rdist and/or rsync operations. Missing validation in the
scp support could result in the bypass of this restriction, allowing the
execution of arbitrary shell commands.

Please note that with the update applied, the "-3" option of scp can no
longer be used.

For the stable distribution (stretch), this problem has been fixed in
version 2.3.4-5+deb9u1.

We recommend that you upgrade your rssh packages.

For the detailed security status of rssh please refer to
its security tracker page at:

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/