From the ServerPronto archive. Historical statements, configurations and offers reflect their original context.
CVE-2014-6217 is a critical vulnerability in all versions of GNU Bash, the Bourne Again Shell.This vulnerability allows an attacker to execute arbitrary shell commands any time a Bash shell executes with environmental variables supplied by the attacker. On cPanel & WHM systems, there are numerous entry points where this vulnerability could be exploited. This blog post from Red Hat demonstrates how such attacks are possible: https://securityblog.redhat.com/2014/09/24/bash-specially-crafted-environment-variables-code-injection-attack/
CVE-2014-7169 is a second vulnerability in all versions of GNU Bash. This second CVE covers attack vectors that were not fixed in the initial updates for CVE-2014-6217. Targeting CVE-2014-7169 is more complicated for an attacker. The authors of GNU Bash are currently working on updates to address CVE-2014-7169. This article from Red Hat has additional details about this flaw: https://access.redhat.com/articles/1200223
On rpm based linux systems (CentOS and Fedora) you can ensure you are updated by running the command "rpm -q bash". The package information displayed should match the version numbers provided by Red Hat at https://access.redhat.com/solutions/1207723
Red Hat Enterprise Linux 7 - bash-4.2.45-5.el7_0.2 Red Hat Enterprise Linux 6 - bash-4.1.2-15.el6_5.1 Red Hat Enterprise Linux 5 - bash-3.2-33.el5.1
Notifications about security updates for Red Hat, CentOS can be found at the following URLs:
Red Hat http://www.redhat.com/mailman/listinfo/rhsa-announce
CentOS http://lists.centos.org/mailman/listinfo/centos-announce
OS maintainers are expected to release additional updates to address CVE-2014-7169. Once these updates are released, you should repeat the update process for the new version of Bash.
What steps do I need to take as an Admin/root of our servers?
First test if your Bash is vulnerable using the below command:
# env x='() { :;}; echo Server is vulnerable' bash -c "echo"
If your server is vulnerable, it will display the message "Server is vulnerable". If your server is secure, the below warning will be shown:
bash: warning: x: ignoring function definition attempt
bash: error importing function definition for `x'
Then on linux systems which use the apt package manager (Debian and Ubuntu) you can ensure you are updated by running the command " bash --version".
To perform an update run "apt-get update && apt-get install bash".
Then on linux systems which use the yum package manager (Fedora and CentOS) you can ensure you are updated by running the command " bash --version".
To perform an update run "yum clean all && yum -y update bash".
For further information and assistance please contact your system administrator.
Your ServerPronto Support Team