Within the configuration management space, people often distinguish between agent-based and agent-less approaches. In short, an agent-based solution means that you install a software agent to run in the background / periodically on the system. That software agent then makes changes to the system as desired, and also commonly communicates over the network to send and receive updates, policy, commands, scripts, data, etc. On the other hand, an agentless system does not involve installing something new, they instead rely on some software which is (presumed) already installed, like the SSH server, which can be used to acces and make changes to the system.
The rather serious recent OpenSSH vulnerability CVE-2024-6387 could affect as many as 14 million server instances exposed on the internet. Let’s make it easy to examine your infrastructure and see if you need to do any upgrades or mitigations.
On the back of my CFEngine T-shirt it says:
Know more, React faster When I have a problem to solve in CFEngine I look for an easy and correct solution. CFEngine Build is a good first place to look. Two modules stand out as possibly useful;
For security reasons, you generally want to uninstall talk, samba, and apache2 in your infrastructure. However, on your webservers, which have the webserver CFEngine class defined, you might want Apache to be installed. With the conditional-installer module, you can put talk,samba,apache2 in the list of packages to uninstall. And in the list of packages to install, you can put apache2 with the condition webserver. Hence, the module will install apache2 on your webservers and uninstall it everywhere else. talk and samba, on the other hand, will be uninstalled everywhere. As always with CFEngine, if the state is already correct - i.e., packages that should be installed are already installed and packages that should not be installed are not installed - no actions will be performed.
Two modules are available for this task: allow-all-hosts and allow-hosts.
The first module, allow-all-hosts, configures the most open situation which is to accept hosts from anywhere. This is only recommended in network restricted environments such as a local machine’s virtual machine network or other such closed down situations.
The second module, allow-hosts, uses cfbs module input to let you decide which hosts (specified by IP addresses and subnets) are allowed to connect to your hub, authenticate, fetch policy, etc. This is by far the more common scenario.
Security Technical Implementation Guides (STIGs) are an excellent body of knowledge to leverage in securing your infrastructure. With the stig-rhel-7 module you can easily add inventory and remediation policy for RHEL 7 with CFEngine. Do note that as of March 2024 this module does not provide comprehensive coverage but rather an initial 10 findings are implemented.
Setup To start I installed CFEngine Enterprise on a local virtual machine, logged in and started a new Build project with the stig-rhel-7 module added and configured to enforce (as opposed to only warn).
We want to bring to your attention a critical security matter recently identified in CFEngine Enterprise version 3.6.0 and subsequent releases. This vulnerability pertains to a A03:2021 - Injection flaw within the CFEngine Enterprise web UI, Mission Portal, which can lead to unauthorized access to the underlying database. The CVE identifier CVE-2023-45684 has been assigned to this issue. At present, there is no evidence to suggest that this vulnerability has been exploited or that it was known beyond the CFEngine development team and the customer who brought it to our attention.
We are writing to inform you about a security issue that was discovered in CFEngine 3.6.0 and later versions. Our development team found the vulnerabiliy relating to inadequate access control / unauthorized access to system files. MITRE assigned the CVE identifier CVE-2023-26560. We have no indications that this vulnerability has been used or known outside of the CFEngine development team.
Explanation The issue is that Mission Portal users can access certain files through scheduled reports, as these reports are run with elevated privileges, without additional checks to limit what can be queried. Within SQL queries (in PostgreSQL) you can use functions like pg_read_binary_file to access files on the file system. This issue is limited to scheduled reports, due to the different context where those queries are run.
Having a list of software that is allowed to be installed on a host is a strategy to prevent and fix security gaps and maintain compliance with operational guidelines. This zero-trust methodology ensures that only explicitly permitted applications are allowed to be present on a host unlike package block-listing which enumerates an explicit list of software that is not allowed to be present. In fact, with a software allow-list, you are essentially block-listing everything except the software you allow.
Can you trust the integrity of your base operating system runtime?
Jason Rogers and Dr. Wesley Peck of Invary join Cody, Craig and Nick to chat about their Runtime Integrity technology. They discuss the challenges of Trust, Information Technology Knowledge Management, and how Invary fits in the SecOps, Systems Automation, Security and Compliance landscape. Nick shares an example of an early integration between CFEngine and the Invary RISe agent1 with reporting in Mission Portal and talks about the different ways to approach integration.
For the holiday season gift yourself an improved infrastructure security posture.
Join Craig, Cody, and Nick as they wrap up 2022 and the 20th episode of “The agent is in” reviewing CFEngines’ 2022 Holiday Security Calendar which has advice picked straight from industry standard security hardening guides like the OpenSCAP Security Policies and Security Technical Implementation Guides (STIGs). Craig demos new modules like maintainers-in-motd, file-permissions, enable-aslr, highlights guidance on writing your own security policies and more.
