In this lesson,
we're going to talk about patch management recommendations
that you may need to make after a pen test is completed.
Patch management is a process of tracking, managing,
and applying patches in a controlled way.
This includes identifying systems that need patches,
testing updates, and documenting which patches
have been applied.
Sometimes, technology limitations prevent patching,
so compensating controls must be put in place instead.
The core aspect of patch management is ensuring systems
are updated with the latest security patches
to protect against vulnerabilities.
This process helps maintain security
and stability by addressing known issues
in software and hardware.
However, many organizations rely on older systems
or have software dependencies that require specific versions
which have vulnerabilities.
This can delay patch implementations
so that the system's availability can be maintained.
It's important to note that not all patches
are sound solutions and patches can come
with additional vulnerabilities
or bugs that affect system availability.
These patches are typically applied first
to lower level environments in larger organizations
to assess the effectiveness and any pitfalls.
If the impact on availability is too great,
organizations may accept the risk at the appropriate level
or implement compensating controls.
Effective patch management follows a structured approach.
Regularly scanning for available patches,
prioritizing them based on the severity
of the vulnerabilities they address,
and applying them properly are the key steps.
A popular method is to categorize them
based on the CVSS score
and set deadlines such as 14 days
for critical vulnerabilities
and 30 days for less critical ones.
So how do you recommend the appropriate remediation
after a pen test?
We start by establishing a comprehensive
patch management process.
This includes regular scanning for available patches,
prioritizing patches based on the severity
of the vulnerabilities,
and applying patches in a timely manner.
Ensure all patches are thoroughly tested
in controlled environments prior to deployment
into production systems.
Document the patch status of all systems,
noting which patches have been applied
and which systems remain unpatched
due to technical limitations.
For unpatched systems, develop and implement
appropriate mitigation strategies
to reduce the associated risk.
Regularly review and update the patch management process
to ensure it remains effective and aligned
with the organization's security policies.
And lastly, we need to make sure
that we're conducting training sessions for IT staff
to ensure they understand the importance of patch management
and how to carry out the process effectively.
Let's look at an example.
Suppose a new critical vulnerability,
CVE-2024-12345
has been discovered in Apache HTTP Server 2.4.57,
widely used on Ubuntu 20.04 LTS web servers,
which allows for remote code execution.
The patch management process begins
by identifying all affected Ubuntu servers
using tools like Nmap and Nessus,
and then obtaining the updated version,
Apache HTTP server 2.4.58,
from official sources.
The patch is first tested in a controlled environment
that mirrors production,
ensuring it doesn't cause any issues.
Once verified, the patch is deployed
during scheduled maintenance windows
using automated tools like Ansible,
followed by post-deployment scans
and monitoring to confirm success.
Records are then updated in the CMDB,
which is a Configuration Management Database
and patch management system.
If patching is not possible on legacy systems,
mitigation strategies such as network segmentation,
increased monitoring, and web application firewalls,
and also strict access controls
are implemented to reduce the risk.
So remember, patch management is an essential practice
for maintaining the security and stability
of your IT environment.
By keeping track of, managing, and applying patches
in a controlled manner,
you can address vulnerabilities identified
during a penetration test
and ensure your systems are protected
against potential threats.