Security Audit Checklist: What Actually Gets Tested

Security audits often feel like a black box. You hire an external firm, they probe your systems for a few weeks, and you get a report full of unfamiliar terms and severity ratings.

Understanding what actually happens during a security audit helps you prepare, reduces findings, and makes the remediation process smoother. Here’s what professional security auditors actually test.

Quick Answer

Audit Phase	What Happens	Duration
Scoping	Define systems, applications, and testing boundaries	1-2 weeks
Reconnaissance	Information gathering about your attack surface	Days to weeks
Vulnerability scanning	Automated tools find known issues	Hours to days
Manual testing	Human testers probe for business logic flaws	1-4 weeks
Exploitation	Attempting to exploit found vulnerabilities	Days to weeks
Reporting	Document findings with severity and remediation	1-2 weeks

Most audits focus on web applications, infrastructure, or both. The scope determines exactly what gets tested.

Vulnerability Categories

OWASP Top 10

The industry standard for web application security testing covers these categories:

Category	What Gets Tested
Injection	SQL, NoSQL, command, LDAP injection in inputs
Broken authentication	Session management, credential stuffing, password policies
Sensitive data exposure	Encryption at rest/transit, data classification
XML external entities	XXE processing vulnerabilities
Broken access control	Authorization bypasses, privilege escalation
Security misconfiguration	Default credentials, unnecessary features, headers
Cross-site scripting	Reflected, stored, DOM-based XSS
Insecure deserialization	Object serialization vulnerabilities
Known vulnerabilities	Outdated dependencies with CVEs
Insufficient logging	Missing audit trails, monitoring gaps

Auditors systematically test each category against your application.

Infrastructure Vulnerabilities

For infrastructure testing, auditors examine:

Area	What Gets Tested
Network security	Open ports, services, firewall rules
Server hardening	OS configuration, unnecessary services
Cloud configuration	IAM policies, S3 bucket permissions, security groups
Container security	Image vulnerabilities, runtime configuration
Secrets management	Credential storage, rotation policies
Patch management	Known vulnerabilities in systems and software

What Manual Testing Catches That Scanners Miss

Automated scanners find known vulnerabilities. Manual testing catches:

Business Logic Flaws

Example	Why Scanners Miss It
Price manipulation	Purchasing items for $0.01
Workflow bypasses	Skipping approval steps
Rate limit bypass	Different endpoints, same action
Privilege escalation	Accessing other users’ data
Coupon stacking	Applying discounts unintended ways

Authentication Edge Cases

Test	What Auditor Does
Password reset flows	Manipulate tokens, race conditions
Session fixation	Force use of known session ID
Token expiration	Use expired tokens, timing attacks
MFA bypass	Skip MFA through alternate flows
Account enumeration	Determine valid accounts through error messages

API Security

Test	What Gets Probed
Authorization	Can user A access user B’s data?
Rate limiting	Does it work? Can it be bypassed?
Input validation	What happens with malformed input?
Information disclosure	Do errors reveal internal details?
Mass assignment	Can attackers modify unintended fields?

Testing Methodologies

Black Box Testing

The auditor knows nothing about your systems beyond what’s publicly visible.

Pro	Con
Simulates real attacker	Misses vulnerabilities that require inside knowledge
Unbiased view	Time-consuming reconnaissance
Tests exposed attack surface	May miss internal-only issues

White Box Testing

The auditor has access to source code, architecture docs, and internal access.

Pro	Con
More thorough coverage	Requires code review skills
Finds deeper vulnerabilities	More expensive
Faster with inside knowledge	May miss what an outsider would find

Gray Box Testing

A middle ground: some internal access, some external perspective.

Most common for application audits: Auditor has user accounts and documentation but no source code access.

Preparing for an Audit

Before the Audit

Preparation	Why It Matters
Define scope clearly	Prevents scope creep, controls costs
Document architecture	Helps auditors understand the system
Run your own scans first	Fix low-hanging fruit before auditors find it
Ensure logging works	Auditors need to see their attacks in logs
Create test accounts	Auditors need access to test authenticated areas
Establish communication	Know who to contact when issues are found

Low-Hanging Fruit to Fix First

Run these checks before auditors arrive:

Check	Tool	Time to Fix
Dependency vulnerabilities	npm audit, Snyk, Dependabot	Hours to days
Security headers	securityheaders.com	Minutes
SSL/TLS configuration	SSL Labs	Hours
Open ports	nmap	Hours
Default credentials	Manual check	Minutes
Exposed admin panels	Manual check	Minutes

Documentation to Prepare

Document	What It Contains
Network diagram	How systems connect
Data flow diagram	Where sensitive data moves
Asset inventory	What systems exist
Access control matrix	Who can access what
Incident response plan	What to do when breaches happen

Understanding the Report

Severity Classifications

Severity	Definition	Typical Response Time
Critical	Immediate exploit possible, severe impact	24-72 hours
High	Significant vulnerability, needs prompt fix	1-2 weeks
Medium	Moderate risk, should be addressed	1-3 months
Low	Minor risk, address when convenient	Next release cycle
Informational	Best practice, no direct vulnerability	As time allows

Common Report Elements

Section	What It Contains
Executive summary	High-level findings, risk assessment
Methodology	How testing was performed
Scope	What was and wasn’t tested
Findings	Detailed vulnerabilities with reproduction steps
Risk rating	Severity and potential impact
Remediation	How to fix each issue
References	Links to CWE, CVE, or other standards

Remediation Process

Triage Findings

1. Critical/High: Fix immediately, verify with retest
2. Medium: Plan for next sprint, document acceptance if deferred
3. Low/Informational: Backlog for future releases

Validation

After remediation, auditors typically perform retesting:

Validation Type	When Used
Full retest	Many critical/high findings
Targeted retest	Specific findings only
Patch verification	Single fix confirmation

Acceptance

Some findings can’t be fixed immediately. Document:

• Risk acceptance: Why the risk is acceptable for now
• Compensating controls: What else mitigates the risk
• Remediation timeline: When it will be addressed
• Owner: Who’s responsible for the risk

Common Findings and Fixes

Finding	Typical Fix
Outdated dependencies	Update to latest versions
Missing security headers	Add CSP, X-Frame-Options, etc.
SQL injection	Parameterized queries
XSS	Output encoding, CSP
Weak password policy	Length requirements, complexity rules
Missing rate limiting	Implement per-endpoint limits
Verbose error messages	Generic errors in production
CORS misconfiguration	Restrict allowed origins
Insecure cookies	Set Secure, HttpOnly flags
Exposed sensitive endpoints	Require authentication, restrict access

Ongoing Security Post-Audit

An audit is a point-in-time assessment. Maintain security with:

Practice	Frequency
Dependency scanning	Continuous (CI/CD)
Static analysis (SAST)	Every commit
Dynamic scanning (DAST)	Weekly or per release
Penetration testing	Annually or after major changes
Security review	For significant features
Incident response drills	Quarterly

---

Security audits aren’t about passing or failing. They’re about understanding your risk exposure and prioritizing remediation. If you’re preparing for an audit or want to assess your current security posture, book a consultation. We’ll help you identify and fix vulnerabilities before auditors find them.