Linux System Scan (Required/Graded)

Linux System Scan (Required/Graded) Previous Next As part of your Vulnerability Management project last week

As part of your Vulnerability Management project last week, you analyzed a report on a Windows system within the company network vulnerable to the MS17-010 exploit. That report was created using OpenVAS, a free vulnerability scanner designed to run on Linux operating systems. Now that you’ve examined a vulnerability assessment report for a Windows machine, it’s time to see what the same tool produces from a Linux system. OpenVAS was used to scan a Linux machine on the network running the company’s database applications. This machine is using an older version of Linux because the company’s database applications are not supported with the latest Linux shared libraries.

This system contains critical data and cannot be taken offline. Your analysis of these two reports should provide you with a good understanding of the OpenVAS tool and the reports you will encounter in the workplace. The report used for this discussion limits the scope to a single host to allow you to focus on the vulnerabilities you would encounter on a Linux machine in the workplace. You will also be able to compare and contrast the vulnerabilities across the two OS platforms. Looking ahead to Project 2’s VM Scanner Background Report (due at the end of Week 5), you will analyze the results from a commercial VM scanner.

You’ll be better prepared to assess the output from the two different vulnerability scanning tools and to form the basis of your recommendation to management. Review Report of Linux Server (OLD) and answer the following questions in your response: 1. For this Linux system, what do you recommend fixing right away? Are there dangers if the vulnerabilities and associated threats are not fixed? 2. How do you fix the problem(s) identified? Can you defer mitigation for another time? How can the problem(s) be fixed if the system cannot be taken offline? Judy is considering asking the pen tester to rescan the company systems using the commercial tool, Nessus. The organization has an evaluation version that can be used for 30 days. After that, the company will need to purchase the tool. The cost is significant. 3. Since some machines were already scanned with OpenVAS, should you also consider scanning the same systems with Nessus? Why or why not? 4. Conduct open source research using the internet. Roughly, what is the cost to license Nessus for one year?

Paper For Above instruction

Analyzing vulnerabilities in Linux systems is a critical component of organizational cybersecurity posture, especially given the ever-evolving threat landscape. The use of vulnerability scanners like OpenVAS and Nessus provides organizations with the ability to identify, prioritize, and remediate security weaknesses in their systems effectively. This paper explores the vulnerabilities identified on a Linux server from an OpenVAS report, recommends immediate mitigation strategies, discusses remediation approaches, and evaluates the consideration of additional tools like Nessus in vulnerability management.

Immediate Vulnerabilities and Associated Dangers

The analysis of the Linux server's OpenVAS report revealed several high-severity vulnerabilities requiring urgent attention. Notably, the report identified outdated packages, unpatched software, and misconfigured services that exposed the server to potential exploitation. For example, unpatched versions of SSH or database services could be exploited to gain unauthorized access, leading to data breaches, data corruption, or complete system compromise. The vulnerabilities associated with outdated shared libraries further increase the risk of arbitrary code execution. If these vulnerabilities are not addressed promptly, attackers could exploit them to compromise sensitive organizational data, disrupt services, or escalate privileges to perform malicious actions.

Mitigation Strategies for Vulnerabilities

Addressing the vulnerabilities involves applying patches to outdated packages, updating shared libraries, and configuring services securely. The process begins with verifying the current system configurations and identifying the specific vulnerabilities from the report. Where possible, patches should be deployed during maintenance windows to minimize operational impact. However, in scenarios where the critical system cannot be taken offline, mitigation can involve using configuration management tools or virtual patching by deploying intrusion prevention systems (IPS) or web application firewalls (WAF). Virtual patches can provide immediate protection until full patches can be safely applied during scheduled downtime.

Deferred Mitigation and Off-line Fixes

In case immediate patching is unfeasible due to the system's critical nature, mitigation can be deferred temporarily, provided compensating controls are implemented. Increasing monitoring, restricting network access, and isolating the vulnerable system from untrusted networks can reduce exposure. For example, implementing network segmentation limits the attack surface and prevents the spread of potential exploits. Nonetheless, prioritizing the quick application of patches at the earliest opportunity is essential, as delays increase risk exposure.

Considering Nessus for Vulnerability Scanning

Judy's consideration of conducting additional scans using Nessus is prudent. Nessus, a commercial vulnerability scanner, offers advanced features like detailed reporting, compliance checks, and more frequent updates, which could uncover vulnerabilities missed by OpenVAS. Given that some systems have already been scanned with OpenVAS, a secondary scan with Nessus can provide comprehensive validation, ensure no vulnerabilities are overlooked, and assist in verifying remediation efforts. Additionally, Nessus’s user-friendly interface and proactive alerts enhance vulnerability management efficiency.

Cost of Licensing Nessus

From open-source research, the approximate cost to license Nessus for one year varies depending on the licensing package. For standard professional use, the annual license fee ranges from approximately $2,390 to $3,190 per user, offering extensive vulnerability scanning capabilities, compliance checks, and support. These costs reflect the value-added features that assist security teams in maintaining secure systems. Organizations need to evaluate these costs against the potential damage from security breaches and operational efficiencies gained through commercial tools like Nessus.

Conclusion

Effective vulnerability management on Linux systems requires prompt identification and remediation of vulnerabilities exposed by scanning tools like OpenVAS. Immediate patches should be prioritized to mitigate high-risk vulnerabilities, with contingency plans including virtual patches and network segmentation for off-line critical systems. Considering additional tools such as Nessus can enhance vulnerability detection and management, justifying its costs with the potential risk reductions. Ultimately, a layered, proactive approach combining continuous monitoring, patch management, and advanced scanning tools is essential for maintaining a resilient security posture.

References

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