=========================================================================Ubuntu Security Notice USN-3946-1
April 11, 2019

rssh vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.10
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS

Summary:

rssh could be made to run arbitrary commands if it received specially crafted
input.

Software Description:
- rssh: Restricted shell allowing scp, sftp, cvs, svn, rsync or rdist

Details:

It was discovered that rssh incorrectly handled certain command-line arguments
and environment variables. An authenticated user could bypass rssh's command
restrictions, allowing an attacker to run arbitrary commands.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 18.10:
  rssh                            2.3.4-8ubuntu0.2

Ubuntu 18.04 LTS:
  rssh                            2.3.4-7ubuntu0.1

Ubuntu 16.04 LTS:
  rssh                            2.3.4-4+deb8u2ubuntu0.16.04.2

Ubuntu 14.04 LTS:
  rssh                            2.3.4-4+deb8u2ubuntu0.14.04.2

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-3946-1
  CVE-2019-1000018, CVE-2019-3463, CVE-2019-3464

Package Information:
  https://launchpad.net/ubuntu/+source/rssh/2.3.4-8ubuntu0.2
  https://launchpad.net/ubuntu/+source/rssh/2.3.4-7ubuntu0.1
  https://launchpad.net/ubuntu/+source/rssh/2.3.4-4+deb8u2ubuntu0.16.04.2
  https://launchpad.net/ubuntu/+source/rssh/2.3.4-4+deb8u2ubuntu0.14.04.2