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Resolving Bash vulnerability in Parallels Virtuozzo Containers

[UPDATE 1st Oct] – More vulnerabilities were reported since this post was originally written on Sep 26th. See the notes at the bottom.

Highly critical Bash code injection vulnerability CVE-2014-6217 was declared on 24th Sep, and a patch is not yet known to be available for Parallels Virtuozzo Containers and Parallels Cloud Servers.

If you have Virtuozzo or Parallels Cloud Server, the individual containers will have Bash; and if you haven’t expressly patched it, assume that your server is vulnerable to hack. Containers typically operate with CGI modules, and they could allow commands to be passed on to Bash, thus opening the gates to hackers.

The engineers in our Proactive Server Management Services detected this threat on 24th, and patched all our Virtuozzo and Parallels Cloud Servers with the following steps:

Login to your hardware node terminal as root, and execute the below script.


for CONTAINER in $(vzlist -a | egrep -w -v "1|CTID" | grep run | awk '{print $1}')
if [[ -f /vz/root/$CONTAINER/etc/redhat-release ]]; 
 if [[ -f /vz/root/$CONTAINER/usr/bin/yum ]]; 
 echo $CONTAINER; 
 vzctl exec $CONTAINER "yum -y update bash";
 echo "yum missing in $CONTAINER. Try again after running, vzpkg install $CONTAINER -p yum";
 echo "$CONTAINER is not RHEL flavor. Possibly Ubuntu or Debian. Modify script to run apt-get command.";

This script lists the containers in the hypervisor, and executes the update command to upgrade bash. In some containers yum might not be present, and you might be required to install yum before continuing.

IMPORTANT : The above script is one of the variations we use to update servers. There is NO guarantee it will work in your server. If you are not sure what these commands are and are not comfortable executing these commands as root, consult a systems administrator.

This should protect your customers from the critical CVE-2014-6217 vulnerability, however, the VPSs will need to be patched again to be fully protected once a solution is available for the related CVE-2014-7169 vulnerability. We will update this post when a patch is available. When the patch is released, just execute the above steps again.

[ UPDATE ] – Patch for CVE-2014-7169 is now available. So, in case you have already ran the commands above, re-run them again to get the final patch.

Critical vulnerabilities are a fact of web hosting. Bobcares Proactive Server Management prevents zero-day exploits by configuring servers for managed auto-upgrades.

Not sure if your servers are patched? We can check your servers for FREE, and optionally patch your servers.

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IMPORTANT UPDATE : New vulnerabilities were reported after Sep 26th (after this post was written). As of Oct 1st, 6 vulnerabilities are reported. Rumors say, more vulnerabilities might be on its way. You need to keep monitoring the threat-scape and update your servers as soon as patches are available.


We can keep an eye on your servers and secure it so that your servers wont be exploited by any of the Bash vulnerabilities. Check out our Bash Special Pro-active Maintenance Service below.

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Bobcares is a server management company that helps businesses deliver uninterrupted and secure online services. Our engineers manage close to 51,500 servers that include virtualized servers, cloud infrastructure, physical server clusters, and more.