USN-3946-1: rssh vulnerabilities

11 April 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

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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

References