I What Is Fuzz Testing

Fuzz testing is a novel way to discover security vulnerabilities or bugs in software applications. Unlike traditional software testing methodologies – SAST, DAST or IAST – fuzz testing essentially “pings” code with random (or semi-random) inputs in an effort to crash it and thus identify “faults” that would otherwise not be apparent. (GitLab Definition)

?1、Fuzzing技术首先是一种自动化技术，即软件自动执行相对随机的测试用例。因为是依靠计算机软件自动执行，所以测试效率相对人来讲远远高出几个数量级。比如，一个优秀的测试人员，一天能执行的测试用例数量最多也就是几十个，很难达到100个。而Fuzzing工具可能几分钟就可以轻松执行上百个测试用例。

2、Fuzzing技术本质是依赖随机函数生成随机测试用例，随机性意味着不重复、不可预测，可能有意想不到的输入和结果。

3、根据概率论里面的“大数定律”，只要我们重复的次数够多、随机性够强，那些概率极低的偶然事件就必然会出现。Fuzzing技术就是大数定律的典范应用，足够多的测试用例和随机性，就可以让那些隐藏的很深很难出现的Bug成为必然现象。

（Fuzzing技术总结）

II Benefits of Fuzz Testing

Because of the random nature of fuzz testing, experts say it’s the methodology most likely to find bugs missed by other tests. It’s also seen as an incredibly low-effort testing methodology, or what some like to call “set it and forget it.” Once the test harness is created fuzz testing is fully automated and will run indefinitely. It can be scaled easily by spinning up more machines and is a good choice for regression testing.

Fuzz testing is also ideal to work alongside a manual testing team as both sets of inputs will educate the other.

1. 更容易发现Bug

2. 开销少

3. 自动化

4. 可以与人工测试协作

III How to Do Fuzz Testing

The steps for fuzzy testing include the basic testing steps:

Step 1) Identify the target system

Step 2) Identify inputs

Step 3) Generate Fuzzed data

Step 4) Execute the test using fuzzy data

Step 5) Monitor system behavior

Step 6) Log defects

(According to here)