Penetration tests often uncover dozens, or even hundreds, of issues. While every vulnerability deserves attention, CISOs face the challenge of prioritizing what truly matters to business operations, customer trust, and compliance obligations.
Not all findings carry the same weight. Some are technical nuisances with limited impact, while others represent direct pathways to data breaches, financial losses, or regulatory penalties.
Knowing which vulnerabilities to track most closely allows CISOs to make smarter risk decisions and allocate resources effectively.
We’ve outlined 10 vulnerabilities that a penetration test might reveal, which CISOs need to monitor and address promptly.
- Unpatched Software with Critical CVEs
Attackers routinely weaponize newly disclosed vulnerabilities within days of release. CVEs tied to widely used software (such as Microsoft Exchange, Apache Log4j, or Fortinet appliances) remain high on the list of pen test findings. These vulnerabilities are often actively exploited in the wild, making timely patching critical.
Example: The Log4Shell vulnerability (CVE-2021-44228) quickly became a global crisis. Organizations that didn’t prioritize patching found themselves open to remote code execution and data theft.
Solution: Establish a formal vulnerability management program with defined SLAs for patching based on severity. Use threat intelligence feeds to prioritize patches for actively exploited CVEs.
- Misconfigured Cloud Storage Buckets
Open Amazon S3 buckets or improperly configured Azure Blob storage are frequent pen test discoveries. These expose sensitive data to the internet without authentication.
Example: A pen test uncovered a cloud bucket that didn’t require authentication, containing HR files, including employee Social Security numbers. The issue could have easily led to a data breach and regulatory fines.
Solution: Enforce least-privilege access and use automated tools (like AWS Config, Azure Security Center, or Prisma Cloud) to scan for misconfigurations. Require encryption and logging by default.
- Weak Authentication and Missing MFA
Passwords alone are not sufficient. Pen tests often reveal weak password policies, commonly used passwords, or systems without multi-factor authentication (MFA).
Example: An internal test revealed admin accounts with commonly used passwords that allowed full access to the ERP system, an easy win for attackers.
Solution: Implement MFA across all critical systems, enforce strong password policies, and integrate single sign-on (SSO) to improve usability and eliminate the use of weak credentials.
- Excessive User Privileges
Overly permissive access controls allow attackers to escalate privileges rapidly once inside the network. Pen testers often exploit unnecessary admin rights or poorly enforced least-privilege policies.
Example: A pen test discovered that marketing team members had database admin rights. This not only increased risk but also created unnecessary compliance violations.
Solution: Adopt a least-privilege access model and conduct regular access reviews. Implement just-in-time (JIT) admin access to limit standing privileges.
- Insecure APIs
With the rise of mobile apps and cloud services, APIs have become prime targets. Common issues include missing authentication, excessive data exposure, or injection flaws.
Example: A pen test found an API endpoint that returned full user records, including PII, without authentication. This flaw could have enabled large-scale data scraping.
Solution: Require authentication for all API endpoints, apply input validation, and enforce rate limiting. Conduct API-specific security testing as part of the development lifecycle.
- Outdated or Unsupported Systems
Legacy applications and operating systems often appear in pen test reports. They may lack security patches or vendor support, making them easy entry points.
Example: A university pen test revealed multiple Windows 2008 servers still in production, exposing the campus to known exploits.
Solution: Build a technology lifecycle management plan that decommissions legacy systems before vendor end-of-support. Where immediate replacement isn’t possible, isolate these unsupported systems on segmented networks with limited access.
- SQL Injection and Other Web Application Flaws
Classic web vulnerabilities like SQL injection, cross-site scripting (XSS), and command injection are commonly present in web applications. Pen testers frequently use these to extract data and pivot to other systems.
Example: A pen tester exploited a vulnerable student portal with SQL injection to extract thousands of records, demonstrating a severe data breach scenario.
Solution: Adopt secure coding practices and frameworks that prevent injection flaws (e.g., parameterized queries). Integrate application security testing (SAST/DAST) into CI/CD pipelines.
- Misconfigured Firewalls and Open Ports
Firewall misconfigurations often leave unnecessary ports open to the internet. Pen testers routinely leverage these weak points for initial footholds.
Example: An organization’s external pen test found an open Remote Desktop Protocol (RDP) port exposed directly to the internet, providing attackers with a direct attack surface for brute force attempts.
Solution: Use automated port scanning and firewall configuration audits. Close all non-essential ports and apply a “deny by default, allow by exception” rule.
- Missing Security Patches in Third-Party Software
It’s not just operating systems; third-party software like CMS platforms, CRM tools, and plugins can harbor critical vulnerabilities.Example: A pen test identified an outdated WordPress plugin that allowed remote code execution, creating a backdoor for attackers.
Solution: Maintain an updated software inventory and enable automated patching wherever possible. Subscribe to vendor security advisories and replace unsupported plugins quickly.
- Poorly Segmented Networks
Flat networks remain a common setup for many organizations. Pen testers often demonstrate how this design makes it easier to access sensitive environments after compromising even a low-value system.Example: A pen tester gained access to a vulnerable kiosk machine in the lobby. Due to a lack of network segmentation, within a few hours, the tester was able to pivot to the financial systems.
Solution: Implement network segmentation by organizing systems based on their roles and sensitivity. Use firewalls, VLANs, and zero-trust principles to ensure lateral movement is limited if one segment is compromised.
Final Thoughts
CISOs face constant pressure to do more with less, and not every vulnerability can be quickly patched. Focusing on the highest impact issues uncovered during pen tests, such as critical CVEs, misconfigurations, weak authentication, insecure APIs, and poor network design, enables smarter prioritization and resource allocation.
By tracking these vulnerabilities, CISOs can make well-informed decisions about remediation, risk acceptance, and long-term strategy. Ultimately, pen test findings should not only be a technical report; they should be a roadmap for reducing business risk.
Contact RedLens InfoSec, CampusGuard’s security division, to conduct a pen test, assess your vulnerabilities, and make a positive impact in strengthening your IT security program.
