How a URL Fuzzer Boosts Your Overall Cybersecurity Posture

Have you ever accidentally typed the wrong thing into a website URL and found yourself accessing a page you’ve never seen before? While you may have arrived there by accident, there are countless attempts by hackers that do the same thing while attempting to locate vulnerabilities in a website. Any developer mistake could become a door through which bad actors gain access to a company’s valuable information, including financials.

What is Fuzzing?

Fuzzing, shorthand for fuzz testing, is the process of searching for bugs within the software that could become a target for hackers. It’s a testing technique that involves sending different variations of data inputs into a target, like a website, to discover potential weaknesses. Essentially, it’s about throwing everything but the kitchen sink at a piece of software or system until something gets through. That differs from a vulnerability scan, which looks for documented security issues. 

With powerful computing resources now available to anyone willing to pay for them, bad actors can spend all day running junk data until they find a bug. It ends up being a never-ending race between hackers trying to exploit vulnerabilities and white hats attempting to stop them. Cybersecurity experts perform fuzzing to try and discover hidden flaws in systems, software, and websites before they become a security liability.

Think about the kind of information held by finance server providers like banks, credit card companies, and investment firms. If a hacker manages to get through to the file system of a company website, think about the kind of information they could access. We’re talking about personally identifiable information (PII) like a client’s home address, bank information, or even social security number.

Any careless coding mistakes that expose that information could lead to a severe cybersecurity incident. According to IBM’s 2019 Cost of a Data Breach Report, the finance industry lost an average of $5.86 million because of stolen data.

How Does a URL Fuzzer Work?

Knowing a website’s files, structures, and directories helps hackers map out an attack strategy. URL fuzzers feed different paths into a website path to expose the hidden structures housed on a website server.

When executed correctly, a URL fuzzer can locate flaws like:

• How a website reacts to invalid or unexpected input
• Any circumstances that could trigger an injection attack
• What conditions cause an application to expose its inner workings or information about the web server, or information leakage
• What situations cause an application to share how its system allocates memory, called a memory leak
• Instances of cross-domain scripting, where a user sends requests to an unintended target, resulting in them exposing sensitive information that compromises a device or server

Security strategists typically apply URL fuzzers in two ways:

• Actively going after a web server — The URL fuzzer uses the web application to send input directly to its scripts and web servers. From there, the URL fuzzier looks to insert data that provokes a specific condition.
• Passively attacking a web application — The URL fuzzer configures a web browser that connects to a website through a URL fuzzer, making the actual web application act as a proxy. That lets the user look for weaknesses by studying how a web browse communicates back and forth with a server.

What Are Some Different URL Fuzzing Techniques?

Here are some common ways testers execute URL fuzzing.

• Random — The URL fuzzer sends random information without relying on a systematic method. You can think of it as banging away on a keyboard without thinking.
• Template — The URL fuzzer reads from a file that tells the program what inputs to use against a website URL.
• Guided — The URL fuzzer uses the website’s behavior to determine the best method of generating an input that exposes a vulnerability.

What Are the Benefits of a URL Fuzzer?

A lot of security testing, like a vulnerability scan, involves trying to understand the precision of the attacks launched by hackers. URL fuzzers try to do the opposite. They look for the kind of unexpected instances that other testing tools may not anticipate. It’s about trying to figure out the seemingly random patterns that could bring down a website through trial and error.

One benefit of URL fuzzing is that it can help testers catch a lot of bugs at once. For example, a tester may use URL fuzzing automation to send thousands of random website URLs to a browser, filling in different paths from a list of potential file names. Then, it keeps running until the process discovers valid paths on the site’s file server.

URL fuzzers help you:

• Locate defects within a web page overlooked during development
• Find vulnerabilities that could be exploited by attacks like SQL injection or denial of service (DoS)
• See how hackers could potentially disable a website’s security protocols and steal data

Protect Yourself From Hidden Vulnerabilities

Havoc Shield’s security program offers the kind of high-level protection required by the finance industry. Learn more about how our product can improve your overall security posture by contacting a Havoc Shield expert to set up a demo.