Hardening assessment and automation with OpenSCAP in 5 minutes

SCAP (Security Content Automation Protocol) provides a mechanism to check configurations, vulnerability management and evaluate policy compliance for a variety of systems. One of the most popular implementations of SCAP is OpenSCAP and it is very helpful for vulnerability assessment and also as hardening helper.
In this article I’m going to show you how to use OpenSCAP in 5 minutes (or less). We will create reports and also dynamically hardening a CentOS 7 server.
Installation for CentOS 7:
yum -y install openscap openscap-utils scap-security-guide
wget http://people.redhat.com/swells/scap-security-guide/RHEL/7/output/ssg-rhel7-ocil.xml -O /usr/share/xml/scap/ssg/content/ssg-rhel7-ocil.xml
Create a configuration assessment report in xccdf (eXtensible Configuration Checklist Description Format):
oscap xccdf eval --profile stig-rhel7-server-upstream \
--results $(hostname)-scap-results-$(date +%Y%m%d).xml \
--report $(hostname)-scap-report-$(date +%Y%m%d)-after.html \
--oval-results --fetch-remote-resources \
--cpe /usr/share/xml/scap/ssg/content/ssg-rhel7-cpe-dictionary.xml \
 /usr/share/xml/scap/ssg/content/ssg-centos7-xccdf.xml
Now you can see your report, and it will be something like this (hostname.localdomain-scap-report-20161214.html):
 
See also different group rules considered:
You can go through the fails in red and see how to fix them manually or dynamically generate a bash script to fix them. Take a note of the Score number that your system got, it will be a reference after hardening.
In order to generate a script to fix all needed and harden the system (and improve the score), we need to know our report result-id, we can get it running this command using the results xml file:
export RESULTID=$(grep TestResult $(hostname)-scap-results-$(date +%Y%m%d).xml | awk -F\" '{ print $2 }')
Run oscap command to generate the fix script, we will call it fixer.sh:
oscap xccdf generate fix \
--result-id $RESULTID \
--output fixer.sh $(hostname)-scap-results-$(date +%Y%m%d).xml
chmod +x fixer.sh
Now you should have a fixer.sh script to fix all issues, open and edit it if needed. For instance, remember that the script will enable SELINUX and do lots of changes to Auditd configuration. If you have a different configuration you can run commands like bellow after running ./fixer.sh to keep SElinux permissive and in case you can change some actions of Auditd.
sed -i "s/^SELINUX=.*/SELINUX=permissive/g" /etc/selinux/config
sed -i "s/^space_left_action =.*/space_left_action = syslog/g" /etc/audit/auditd.conf
sed -i "s/^admin_space_left_action =.*/admin_space_left_action = syslog/g" /etc/audit/auditd.conf
Then you can build a new assessment report to see how much it improved your system hardening (note I added -after to the files name):
oscap xccdf eval --profile stig-rhel7-server-upstream \
--results $(hostname)-scap-results-$(date +%Y%m%d)-after.xml \
--report $(hostname)-scap-report-$(date +%Y%m%d)-after.html \
--oval-results --fetch-remote-resources \
--cpe /usr/share/xml/scap/ssg/content/ssg-rhel7-cpe-dictionary.xml \
 /usr/share/xml/scap/ssg/content/ssg-centos7-xccdf.xml
Additionally, we can generate another evaluation report of the system in OVAL format (Open Vulnerability and Assessment Language):
oscap oval eval --results $(hostname)-oval-results-$(date +%Y%m%d).xml \
--report $(hostname)-oval-report-$(date +%Y%m%d).html \
/usr/share/xml/scap/ssg/content/ssg-rhel7-oval.xml
OVAL report will give you another view of your system status and configuration ir order to allow you improve it and follow up, making sure your environment reaches the level your organization requires.
Sample OVAL report:
Happy hardening!

Prowler: an AWS CIS Security Benchmark Tool

screenshot-2016-09-14-22-43-39In this blog post I’m happy to announce the recent release of Prowler: an AWS CIS Security Benchmark Tool.

At Alfresco we run several workloads on AWS and, like many others companies, we use multiple AWS accounts depending on use cases, projects, etc.

To make sure we have a foundation security controls applied to each  account, AWS counts with a service called Trusted Advisor which has, among other features, a section for Security Best practices, it checks some services and give us some recommendations to improve Security of our account, 3 checks are free the rest of them (12) are available only for customers with Business or Enterprise support plan:

screenshot-2016-09-14-17-26-09

Trusted Advisor is fine, but it is not enough comprehensive and it is not free. Here is a screenshot of Trusted Advisor in the AWS Console on a Business support plan account:
screenshot-2016-09-14-17-30-09

In addition to that AWS service, few months ago the Center or Internet Security (CIS) along with Amazon Web Services and others, released the CIS AWS Foundations Benchmark. In that document we can find a collection of audit checks and remediations that cover the security foundations for these main areas in AWS:

  • Identity and Access Management (15 checks)
  • Logging (8 checks)
  • Monitoring (16 checks)
  • Networking (4 checks)

The 89 pages guide goes through 43 recommendations by explaining why that check is important, how to audit it and how to remediate it in case you don’t have it properly configured.

If you try to follow all these checks manually it may take you a couple of days to have all of them checked. This is why in Alfresco we decided to write a tool to make it faster, thus I wrote “Prowler”, a command line tool based on AWS-CLI that creates a report in a minute and shows you how is your AWS account configured in terms of security (using fancy color codes).

screenshot-2016-09-13-09-31-07

Prowler, whose name comes from the Iron Maiden song with the same name, works in Linux, OSX and Windows (with Cygwin), with AWS-CLI installed. It also requires an AWS account with at least the SecurityAudit policy applied as specified in the documentation. For more information, details and sample reports visit the project repository in Github here https://github.com/toniblyx/aws-cis-security-benchmark.

Please, go ahead, check it out and give me feedback!

Hope it helps!

UPDATE! Right after I published this post, I was pointed in Twitter by @MonkeySecurity about Scout2, which is a tool we use here since long time and it is very helpful. It has many different checks and it is complementary to Prowler, don’t forget to give it a try! And also use SecurityMonkey if you are not doing so already!

UPDATE2! Another tool to perform AWS security checks is the CloudSploit Scans, more info here.