How I Remediated Vulnerabilities Found on My Client’s Network?

As a security analyst and consultant, one of my most important responsibilities is helping clients remediate vulnerabilities found in their networks. Recently, I was brought in to assess and enhance the security posture of a mid-sized financial services company.

Upon running comprehensive vulnerability scans, I discovered over 5000 vulnerabilities across their environment. Many were related to unsupported operating systems, unpatched software, and misconfigurations. Facing such a complex situation, I knew an organized, strategic approach would be required to fix vulnerabilities effectively.

In this blog post, I’ll walk through my process for prioritizing, remediating, and confirming the resolution of the vulnerabilities uncovered in my client’s network.

Prioritizing What to Fix First

With thousands of vulnerabilities detected, attempting to tackle them all at once would have been ineffective and disrupted business operations. Instead, I worked with the client to prioritize remediation based on risk severity and business impact.

We placed vulnerabilities into buckets using the CVSS scoring system:

  • Critical (9-10) – Fix immediately

  • High (7-8) – Fix within 2 weeks

  • Medium (4-6) – Fix within 1 month

  • Low (0-3) – Fix within 3 months

Additionally, we prioritized vulnerabilities in customer-facing systems and apps handling sensitive data for faster turnaround. Grouping vulnerabilities this way enabled methodical and risk-based remediation.

Eliminating False Positives

Before rushing to apply patches or make configuration changes, I first had to identify false positives – findings reported as vulnerabilities that don’t actually pose risk.

The key to eliminating false positives is researching how the scanning engine detects each vulnerability, then verifying its presence on the specific system. For example, apparent vulnerabilities related to Chrome being flagged on systems not showing the browser installed in Add/Remove Programs.

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By searching the local drives, I discovered remnant Chrome files in a user’s profile causing false detections. Proper investigation averted unnecessary “remediation” that could have caused operational disruption. Out of the initial 5000+ findings, I was able to cull 20% as false positives. Still, 4000+ legitimate vulnerabilities remained.

Deploying Patches

For operating systems and common software like Java and Adobe, I deployed patches across the environment using Microsoft SCCM. Leveraging its automated testing, phased rollout, and scheduling capabilities enabled efficient remediation with minimal business impact.

Within two weeks, we patched critical OS vulnerabilities on over 85% of systems, eliminating the highest priority attack vectors.

Reconfiguring Services

While patching addresses vulnerable code, configuration changes are required to fix vulnerabilities introduced by insecure settings. Using the scanning results and consulting the Center for Internet Security (CIS) benchmarks, I worked with the client’s IT team to develop secure configuration baselines per system type (ex. Windows Server, Linux, etc.)

We then utilized SCCM and other tools to reconfigure services like SSH, TLS, and databases to adhere to these baselines. Though more time-consuming than patching alone, addressing configuration-oriented vulnerabilities was essential to boost the overall security posture.

Confirming Remediation

After vulnerability remediation within designated timeframes, I rescanned to validate successful resolution based on the absence of the original findings. In most cases, vulnerabilities were able to be eliminated from the environment.

However, in some specialized systems, vulnerabilities persisted due to factors like compatibility concerns and legacy tech constraints. For these, I ensured proper documentation of accepted risks, temporary workarounds, and plans to eventually decommission or upgrade these platforms.

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Rescanning – and confirming remediation where possible – completed the vulnerability management lifecycle, helping transform the security posture of my client’s environment.

Achieving Security Success

In closing, I was able to successfully prioritize and remediate over 85% of critical and high-risk vulnerabilities across my client’s network in just two month’s time. This significantly reduced their exposure to cyber threats, decreased attack surface, and improved security outcomes.

While more work remains to address less severe vulnerabilities, the client can now make data-driven business decisions on further investment to manage residual risks. My experience reinforces that, even in very complex situations, methodical vulnerability remediation can deliver tremendous security dividends. Proper planning and processes pave the path to impactful risk reduction.

Let me know if you have any other questions on securing vulnerabilities within your environment! I’m always happy to chat.

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