- Sep 06, 2023
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As an ethical hacker, one of the most important services I offer clients is comprehensive website security audits. I get to flex my cyber sleuthing muscles and help organizations uncover risks before the bad guys do. But methodical planning is required – you can’t just wing a site audit.
In this step-by-step guide, I’ll demystify how to properly audit website security, sniff out weak points, and deliver value to clients. Let’s put on our detective hats and dive in!
Gather Initial Site Intel
Recon is where every website audit starts. I want to know as much as possible about the site before getting hands-on. Important intel to gather:
- Domain name, IP addresses, hosting provider, technologies used
- Site content, functionality and architecture
- Administrators, developers, third-party connections
- Current security controls like WAFs, firewalls, SSL
OSINT tools help compile this data quickly without accessing the site directly. For example,BuiltWith reveals technologies and connections while Netcraft provides hosting info and site history.
This profile equips me to conduct more targeted, insightful testing later. It also may reveal low-hanging vulnerabilities like expired certificates I can immediately flag. Knowledge is power!
Map the Attack Surface
Next I create a comprehensive map of the website’s attack surface – all points where users interact with the app. This helps focus testing on areas where vulnerabilities would cause most harm if exploited.
I inventory every:
- Page, form, link, button, field
- Data input or output
- API endpoints
- User roles and privileges
- Back-end connections to databases, payment systems, etc.
Crawling the site manually while tracking everything in Burp Suite is tedious but necessary. This map becomes my master checklist to test later.
Analyze Access Controls
Understanding how the site handles access and authentication is crucial. I investigate:
- How users register and login
- The password policy, reset flow, and account lockouts
- Session length, token generation, and logout processes
- Account roles and what functionality each permits
- Resources protected behind login vs publicly accessible
Poor access controls easily enable account takeovers, leaked data, unauthorized changes, and more. Rigorously testing them takes priority during an audit.
And if I spot weak practices like plain text passwords, I’ll raise them immediately rather than waiting for the final report. Tick tock – that time bomb needs defusing ASAP before it’s too late!
Check Initial Vulnerability Scan Results
Next I’ll run some initial automated scans with tools like Netsparker, Acunetix, and Nessus. The findings generate a baseline understanding of common issues like:
- Injections flaws
- Cross-site scripting bugs
- Broken authentication
- Sensitive data exposure
- Security misconfigurations
- Outdated libraries with known vulnerabilities
The volume of vulnerabilities can be overwhelming, so I filter and prioritize the results based on severity and exploitability. For now, I mainly want a sense of the site’s general security hygiene before testing manually.
Attempt Illicit Access Exploits
This is where I get hands-on trying to exploit vulnerabilities like a real attacker would. I spend most of my time probing key areas already identified:
Injection attacks – I’ll perform SQL, OS, and LDAP injection attempts to see if I can manipulate or extract data.
Cross-site exploits – Scripting, request forgery, and spoofing attacks help test integrity checks.
Broken authentication – I’ll hammer account login and passwords from all angles to spotlight weaknesses.
Access bypass- Trying privilege escalation, direct object references, or path traversals can uncover authorization holes.
The goal is demonstrating actual compromise scenarios based on the highest risks, not just theoretical vulnerabilities. I exploit flaws aggressively but ethically to prove the damage potential.
Evaluate Session Management
Flaws in session management are some of the most dangerous holes. I specifically assess:
- Session cookie strength, expiration, and encryption
- How session IDs are created
- Whether sessions expire properly on logout
- If session data is leaked elsewhere
- Ways to predict, steal, fixate, or tamper with session IDs
Poor session management equals compromised user accounts and data. Given its risks, I rigorously test and attempt to defeat the site’s session protections.
Assess Risk of Input Attacks
Next I’ll methodically test all forms, fields, inputs and outputs I’ve inventoried for vulnerabilities. This includes:
- Fuzzing inputs with invalid data to check error handling
- Overflow attacks aimed at buffers and strings
- Manipulating data formats like XML and JSON
- Testing edge cases on numerics, unicode, and special chars
- Checking for default creds or predictable values
Proving just how dangerous unchecked inputs can be builds a compelling case for sanitization and validation defenses.
Evaluate Security Headers and Settings
A site’s HTTP response headers and security-related configuration settings reveal much about its defenses. I’ll check for:
- Strict-Transport-Security and Content-Security-Policy
- X-Frame-Options to prevent clickjacking
- X-XSS-Protection to stop cross-site scripting
- Server type and version – risks if outdated or uncommon
I also test Sundry web.config, robots.txt and cross-origin resource sharing settings that impact security. Bad configurations can completely undermine other defenses.
Launch a Password Attack
Next I’ll leverage password lists and cracking tools like John the Ripper to launch dictionary, brute force, and rainbow table attacks if allowed. This tests the strength of password policies and account lockouts.
Even if I can’t access user accounts directly, I may be able to reset or brute force my way into forgotten password flows. Any weak points here demonstrate the need for stronger pass policies.
Check for Platform Vulnerabilities
If the web technology is known like WordPress or Drupal, I scan for platform-specific vulnerabilities by:
- Fingerprinting the CMS version
- Researching known exploits for that version
- Scanning plugins/themes/add-ons for vulnerabilities
- Checking admin consoles for common misconfigurations
- Abusing default settings and sample content
Keeping platforms patched and properly configured is crucial. I demonstrate what happens when organizations get lazy with updates!
Execute a Realistic Attack Scenario
All these assessments inform a hypothetical attack scenario I’ll execute at the end. This combines multiple exploits to show their combined damage potential. For example:
- Use SQL injection to extract password hashes
- Crack hashes to hijack admin accounts
- Plant backdoor malware via file upload bug
- Manipulate session cookies to impersonate users
- Scrape sensitive data now accessible
This shows the devastating domino effect from seemingly minor and unrelated vulnerabilities. Attackers think in combinations, so defenders must too!
Deliver a Comprehensive Report
After thoroughly probing the site’s security, I compile insights into a report. This includes:
Summary of Main Risks – I focus on big picture issues and realistic attack scenarios, not just individual bugs.
Technical Details – Raw findings get categorized by risk severity and vulnerability type. But I translate techie terminology into plain language.
Prioritized Recommendations – I provide practical remediation guidance tailored to the client’s environment and skill level. Quick wins first!
Appendix of Raw Test Data – For completeness, I include full scan reports, scripts, request/response dumps, and screenshots.
This comprehensive report distills everything into an understandable narrative clients can act on. I offer to walk through findings in person and discuss next steps.
Follow Up and Retest
Months later I’ll retest to see what recommendations were implemented. I’ll praise improved security while again demonstrating any ongoing issues that still require remediation.
These follow up assessments build accountability and track security posture over time. Clients improve most when they know I’ll be back to re-evaluate! A single audit is just the start of an ongoing partnership.
And there you have my start-to-finish website security audit methodology! Well, at least the non-proprietary parts. I’ve surely omitted a few secret sauces.
But hopefully this overview conveys how much meticulous planning, research, skill and care goes into a professional-grade audit. It’s certainly not something you can fully automate. Human intuition and custom exploits are still invaluable.
Websites provide infinite attack surfaces, so comprehensive testing is essential. Don’t settle for slapdash scans or generic audits. Invest in rigorous assessments, fix what matters most, and keep testing to stay ahead of threats. Your users will thank you!
Now if you’ll excuse me, it’s time to brew some coffee and dive into another stimulating site audit. Let’s see what vulnerabilities I can unearth today!
Choosing the Right Web Security Audit Tools
Skilled auditors can uncover many vulnerabilities manually. But web security crawls at the speed of automation. The right tools greatly amplify an auditor’s powers. Here are some of my go-to utilities:
Burp is an indispensable Swiss army knife for web security testing. As an intercepting proxy, Burp lets me manipulate traffic in transit to inject payloads, bypass protections, and map out functionality.
Burp’s scanner automatically detects common vulnerabilities. I can also perform manual testing via the repeater, decoder, and intruder tools. Extensions provide everything from brute forcing to mobile app scans.
For web audits, I rely on Burp nearly every step of the way to dissect apps. It’s absolutely essential.
ZAP is another robust web scanner focused on finding common vulnerabilities like injections, XSS, broken auth, and more. As an open source tool, ZAP benefits from constant community contributions and expansions.
I often run ZAP scans in parallel with Burp for additional visibility. It also features automated penetration testing modes useful for audit replays and regressions.
While not web-specific, Nmap allows discovery of infrastructure and assets that impact web security. Nmap scans networks for connected devices, open ports, services, and vulnerabilities.
This helps me inventory web servers, databases, APIs, mail servers and more that touch the web app. Mapping the broader infrastructure reveals unseen risks.
Nikto is a veteran web scanner tuned for finding server and web app configuration issues like outdated software, default files and settings, dangerous HTTP methods, and more. It’s great for fingerprinting and profiling.
While it won’t find logical vulnerabilities in code, Nikto excels at quickly finding weak configurations overlooked by other tools. It’s ideal for initial recon.
Collections of common passwords, snippets, directory names, subdomains, URLs, and more are invaluable during web audits. Wordlists turbocharge brute forcing, URL guessing, input fuzzing and parameter mining.
Web Security Testing Methodologies
Experienced auditors don’t just run tools haphazardly. We follow meticulous methodologies refined over years of battle-testing. Here are key web audit procedures I adhere to:
Map the Attack Surface
As described previously, I spend lots of time upfront mapping out every endpoint, input, data store and component in scope. This inventory focuses subsequent testing only on relevant areas.
Things change fast, so I revalidate the attack surface before starting. Prior audits or old sitemaps quickly become outdated as sites evolve.
Compare Multiple Scanners
Relying on just one scanner is asking for blindspots. Each scanner looks for vulnerabilities differently. I run multiple to compare results and minimize missed issues.
Nikto finds config problems that Burp misses. Burp finds logical flaws other scanners don’t. I leverage 5-6 scanners during assessments to validate findings across tools.
Test Authentication and Authorization
At least half of every web audit focuses on access controls and session management. If I can bypass login or impersonate users, nearly all other findings become irrelevant.
I attempt every conceivable login bypass using tools like Burp and custom-written scripts. Proper access protections make exploitation 100x harder.
Customize for the Platform
Testing differently powered WordPress vs. React sites requires tailoring approaches. Once I fingerprint the platform, I select applicable plugins, scripts and wordlists.
Platform-specific scanners like WPScan for WordPress along with platform docs also guide testing. Know the technology to find its hidden flaws!
Replay Tests as Issues Are Fixed
I re-run tests multiple times throughout an audit lifecycle as original findings get remediated. This validates whether issues are truly fixed while identifying regressions.
Ongoing retesting like monthly web audit “sprints” help address the evolving attack surface. Don’t just scan once! Follow-up assessments build accountability.
These and many other procedures separate strategic web audits from casual scans. Methodology matters. With rigorous methodology and versatility across tools and techniques, I can deliver audits with maximum impact.
Presenting Security Audit Results Persuasively
An audit has little value if you can’t explain findings convincingly to catalyze action. Charts, stats, risk estimates, impact dollars – these persuade executives to address security risks. Here are some reporting best practices:
Quantify the Risks
I calculate statistics like percentage of flaws addressed since the last audit, types of vulnerabilities over time, attack surface growth rates, etc. These spotlight trends and progress.
For critical bugs, I estimate exploitation likelihood based on real-world attack data. I also project costs if exploited using actuarial models. Hard numbers hit home more than just technical risks.
Visualize Key Data
Charts, graphs, and visuals help condense complex results into memorable snapshots. For example, pie charts showing vulnerability categories or timelines of issue types over multiple audits.
I tailor visuals to organizational priorities and metrics using BI tools. CISOs think in graphs – I speak their language visually.
Compare Against Benchmarks
I enrich reports by comparing client metrics like vulnerability densities, security spend, and patching cadence against anonymous industry benchmarks. This provides perspective on their maturity.
For example, I can show a client that their exposure rate of risky open source libraries is X times higher than average in their sector. Benchmarks motivate improvement.
Highlight What’s Improved
I deliberately spotlight areas that have strengthened since previous audits before diving into ongoing gaps. This positive reinforcement incentivizes security progress.
Incremental improvements towards benchmarks, not just the remaining flaws, deserve emphasis. Marathon, not sprint – accent wins to build momentum.