I was facing problem in arranging my thoughts on how I can manage the vulnerability scan results of the servers and other equipment on my network. I wrote this article to bring the results of the research that I performed in this field to help others in managing the vulnerabilities and resolve it as soon as possible. Because the main factor in vulnerability management is time as soon as you resolve it as soon as you will be secure.
Vulnerability assessment (VA) is part of the vulnerability management (VM) tasks that the security professional perform on regular basis. The first step in any VM task is to discover your network and find all the assets you have to assess the vulnerabilities on it. So, you need a tool to map and discover your network and run it. Keep in mind to perform the discovery scan on a frequent basis to keep your asset list up to date. The second step reviews the results and group the assets based on an operating system that assets run on. The method I used to group the assets is:
- Windows OS.
- Linux and Unix ( I used generally Unix)
- Network equipment
This grouping will help in running the vulnerability assessment on scheduled base for frequent periods. For example, the Windows group can be scheduled on first Friday of the month to scan all windows assets. Schedule the second group to run on second Friday of the month and etc. Choosing the time of the scan on weekend better to avoid the overhead happens on the network and to review and analyze the results on the first working day of the week. Always review your results of discovery and grouping with the admins on each group to help in making the grouping more accurate.
As the results of the vulnerability scan are ready with you. You can start the next stage which is the reporting. Always better to filter the most critical high severity vulnerabilities as the first step to resolve the vulnerabilities with admins. So, I recommend structuring the vulnerability management task to start with the reports showing high severity exploitable vulnerabilities to be resolved. That is better to make the task easy to be managed and easy to be tracked by admins and the security professional working on this task. Then as the second stage of reporting produce reports with the remaining vulnerabilities with lower severity.
For reporting it is recommended to group the assets as groups based on application/solution running on the assets/servers. For example Domain Controllers group, Exchange group, ...etc. Grouping based on application/solution will make the task much easier for the admins to patch the servers and test the patch. Because the main problem with the admins is to test the patching needed to resolve the vulnerabilities it is usually will make a problem with the application running on these servers. Like compatibility issues.
Reporting the vulnerabilities can be categorized into two categories: admin reports and management reports. Admins report is more technical details reports that show the servers details with the vulnerabilities related to it. Details of admins report contains only the relevant information needed to the admin to avoid confusion and the report can list all the vulnerabilities with a brief description of the vulnerability and the solution for the vulnerability usually mention the configuration or the patch needs to be applied to solve that vulnerability. On the other hand, Management report should show the total vulnerabilities of all servers in graphic and summary counts view that explains the status of the vulnerabilities in the organization network. Finally, share high severity exploitable vulnerabilities reports with the concerned persons.
In this stage, security professional created the structure of the vulnerability management task in a way that can be tracked with the related admins and they have to start the follow-up and SLA stage to resolve the vulnerabilities as soon as possible. This task can be performed using excel sheet or dedicated solution to track the resolved vulnerabilities.
Finally, vulnerability management is a task that is must be accomplished on a frequent basis. Monthly is a good frequency to give the time to resolve the vulnerabilities.
By Abdulla Abusaif, CISSP, PMP