CVE-2017-16021 Explained : Impact and Mitigation

The uri-js module, up to and including version 2.1.1, is vulnerable to a denial of service (DoS) attack due to a regular expression vulnerability that causes high CPU utilization.

Understanding CVE-2017-16021

This CVE identifies a vulnerability in the uri-js node module that can lead to a DoS condition.

What is CVE-2017-16021?

The uri-js module, designed to implement RFC 3986, is prone to a regular expression denial of service (redos) vulnerability, impacting versions up to and including 2.1.1.

The Impact of CVE-2017-16021

The vulnerability allows an attacker to trigger a DoS attack by exploiting the regular expression vulnerability, causing the CPU to reach 100% utilization and rendering the program unresponsive.

Technical Details of CVE-2017-16021

The technical aspects of the vulnerability are as follows:

Vulnerability Description

The vulnerability arises from a flawed regular expression used for URL validation in the uri-js module.

Affected Systems and Versions

Product: uri-js node module
Vendor: HackerOne
Versions Affected: <=2.1.1

Exploitation Mechanism

The vulnerability can be exploited by sending malicious input to the

require("uri-js").parse()

function.

Mitigation and Prevention

To address CVE-2017-16021, follow these steps:

Immediate Steps to Take

Update the uri-js module to a version beyond 2.1.1 to mitigate the vulnerability.
Avoid accepting user input in functions that interact with the uri-js module.

Long-Term Security Practices

Regularly monitor for security advisories related to the uri-js module.
Implement input validation mechanisms to prevent malicious input.

Patching and Updates

Apply patches or updates provided by HackerOne to fix the vulnerability in the uri-js module.