Most Common Weaknesses ProArch's Penetration Testing Uncovers

Penetration testing (pen test) helps uncover gaps in an organization’s security posture by simulating real-world attacks. It validates whether vulnerabilities across applications, networks, wireless infrastructure, physical environments, and human behavior can actually be exploited — not just whether they exist.

At ProArch, we’ve performed hundreds of penetration tests across industries and organization sizes. These assessments use internal, external, and assumed-breach testing to reflect how attackers gain access, escalate privileges, and move laterally through environments.

In this blog, we cover the five most common exposures and why they’re so common.

Unsecured File Shares with Sensitive Data

Network file shares are meant to make collaboration easy, but they’re often overlooked from a security standpoint. Because access is usually broad, attackers and penetration testers target them early.

Why file shares get exploited:

• Easy to access
• Sensitive data piles up over time

Files stored on these shares often help attackers understand the environment and move to other systems like servers, applications, and email. In penetration tests, exposed scripts and cleartext passwords on file shares have led to full domain compromise. Unsecured file shares are a common starting point for privilege escalation and lateral movement.

Privileged Accounts Running as Service Accounts

Service accounts are often created quickly to support applications and integrations. Over time, they end up with more access than required and little ongoing oversight.

Why this becomes a real risk:

• Excessive privileges: Service accounts are often granted admin-level access instead of least privilege.
• Shared or unmanaged credentials: Passwords are reused, rarely rotated, or embedded in scripts.
• Limited auditing: Activity from service accounts is rarely monitored or reviewed.

Over-privileged service accounts give attackers broad access with little resistance.

Weak or Default Passwords

Weak or default passwords are still some of the easiest issues to exploit during penetration tests. They are most commonly found on multifunction devices such as printers and scanners, as well as on forgotten or poorly managed service accounts.

Why this remains a common weakness:

• Default credentials on devices: Printer and network device passwords are often publicly documented and rarely changed.
• Forgotten service accounts: Old or unused accounts retain weak passwords and elevated access.
• Excessive privileges: Devices and service accounts often have more access than required.
• Credential reuse: Once obtained, the same credentials are reused across systems.

Simple access to a printer interface or address book has led to full network compromise more often than expected during penetration tests. Email addresses, system details, and other sensitive information become immediately accessible.

One weak or default password is often enough to escalate privileges and move laterally across the environment.

Bypassing Misconfigured Cybersecurity Solutions

Security tools are often deployed with good intentions, but misconfiguration and lack of ongoing management reduce their effectiveness. When controls aren’t enforced or monitored correctly, attackers can bypass them without being detected.

Why misconfigured tools get exploited:

• Incomplete implementation: Security tools are installed but not fully configured to block real attack techniques.
• Default or weak settings: Out-of-the-box configurations leave gaps attackers can abuse.
• Lack of monitoring and response: Alerts are generated but not reviewed or acted on in time.
• Tool sprawl and ownership gaps: Multiple tools create confusion around responsibility and response.

When security controls fail, attackers gain time and freedom to move through the environment undetected.

Security tools only protect the environment when they’re properly configured, monitored, and continuously validated.

Inadequate Network Segmentation

Many environments still allow critical systems and less secure assets to exist on the same network. Once attackers gain an initial foothold, poor segmentation makes it easy to move deeper into the environment.

Why segmentation gaps get exploited:

• Flat network design: Internal systems can communicate freely with little restriction.
• Overreliance on perimeter defenses: Security controls focus on keeping attackers out, not limiting movement inside.
• Legacy architectures: Older network designs were not built to support modern threat models.
• Minimal internal access controls: Internal traffic is often trusted by default.

Without clear boundaries, a single compromised system can quickly lead to broader access.

Think you’re secure? ProArch will be the judge of that.

At ProArch, we don’t just perform penetration testing services—we help fix the gaps and provide ongoing cybersecurity solutions once the pen test is done. Don't rely on only a vulnerability scan as a measurement of your security posture.

•  We perform pen testing in-house. Our team is the only one to access your environment.
• You won’t be redirected to another vendor for remediation. We can guide you through remediation, or we can do it for you.
• We have done 100 pen tests and have all the required certs. We've been in cybersecurity space for 20+ years.
• Our pen test reports are tailored to your needs. Informative and actionable is how our pen test reports are consistently described.

Know what's really putting you at risk, get a plan for remediation, and focus your investments where it matters most. Reach out to us.