After hundreds of engagements, the same weaknesses appear again and again. The uncomfortable truth is that most successful attacks do not rely on exotic zero-days; they exploit basic, preventable issues that organizations keep getting wrong. Here are the vulnerabilities penetration testers find most often — and why they matter.
1. Broken and weak access control
Users accessing data or functions they should not, insecure direct object references, and missing authorization checks remain the single most common category. It tops the OWASP Top 10 for good reason — it is everywhere, and it leads directly to data exposure.
2. Weak, default, and reused credentials
Default passwords left in place, weak password policies, credentials reused across systems, and missing or poorly implemented multi-factor authentication give attackers an easy way in. Identity is the primary battleground, and this is where it is lost.
3. Missing patches and vulnerable components
Unpatched systems and outdated third-party libraries are a perennial finding — and exactly what perimeter-focused groups like Fox Kitten exploit. Internet-facing systems that are months behind on patches are low-hanging fruit.
4. Security misconfigurations
Exposed admin interfaces, overly permissive cloud storage, default settings left unchanged, and unnecessary services dramatically expand the attack surface. Cloud misconfiguration in particular has become one of the leading causes of data exposure.
5. The recurring rest of the list
- Injection flaws such as SQL and command injection.
- Hardcoded secrets and credentials in code and configuration.
- Insufficient logging and monitoring, which lets intrusions go unnoticed.
- Susceptibility to phishing and social engineering among staff.
The common thread
Almost all of these are basics done imperfectly, which is good news: they are fixable. The lasting solution combines testing to find them, remediation to close them, monitoring to catch what slips through, and people who do not fall for the lure. Persist Security delivers penetration testing with prioritized remediation guidance, security awareness training to harden your people, and a managed SOC to catch the logging-and-monitoring gaps. Contact us to find and fix your most exploitable weaknesses.
