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How to detect the Log4j vulnerability in Java projects for free with Contrast Security's CodeSec

How to detect the Log4j vulnerability in Java projects for free with Contrast Security's CodeSec

Log4j is a popular Java logging tool with a critical cybersecurity vulnerability that gained global attention in December 2021.  The U.S. Dept. of Homeland Security’s Cyber Safety Review Board stated in a recent report that it is one of the most serious vulnerabilities seen in years. Because of the popularity of the Log4j tool with Java developers, the problem is an “endemic vulnerability” for the software industry, according to the board. Luckily, we can identify this log4j security vulnerability in Java projects at no cost with the fastest and most accurate free scanner in the market, CodeSec by Contrast! 


1. Get CodeSec to Detect Log4j Vulnerability

For this walkthrough on how to begin to detect Log4j vulnerabilities, we will use both CodeSec and a demo of the Log4j exploit. The first step is to get CodeSec onto your machine.  Contrast Security has great instructions on our Developer Central hub for getting started with CodeSec, but we will review the process here as well.


a. Install CodeSec

As of August 2022 Contrast Security offers three options for installing CodeSec: Homebrew for MacOS, NPM for any operating system running newer NodeJS versions and binaries through Artifactory.

For this example we will be using NPM:
Run Command: npm install -g @contrast/contrast

NPM Install

Pro tip: Running the command contrast help will show you the usage guide if the install has gone successfully.

Pro Tip


b. Authenticate

Authentication is needed to access Contrast Security’s enterprise-class cybersecurity services through CodeSec. You can use your existing Github or Google account to authenticate.

To authenticate, run the command contrast auth


A tab will then open in your browser, asking you to finalize your authentication by connecting with your existing Google or GitHub account.

Google Github

Note: When completing the authentication steps for the first time, your command line may disconnect and output a message stating that the authentication session has timed-out. But do not worry! By re-running the command contrast auth, a new browser window will open, and this time when the initial path chosen to authenticate (GitHub or Google) is clicked, the window will immediately redirect to the Success page, and your terminal will output an “Authentication successful” line.

Contrast Auth

Screenshot 2023-06-27 at 4.35.18 PM

Now that CodeSec is set up to use locally, the next step is to get a demo of the Log4j vulnerability.


2. Log4j vulnerability

The NIST National Vulnerability Database’s page on the Log4j vulnerability has a wealth of resources about this security concern, including links to demo projects with example code implementing the vulnerability.

One linked project is the “Apache Log4j2 2.14.1 Remote Code Execution” project from Packet Storm (available here).  It is a very minimalist proof of concept project that includes vulnerable versions (in this case, 2.14.1) of the Log4j libraries as Maven dependencies in the project’s pom.xml file.

Once you have the project downloaded and unzipped locally, you can check it for vulnerable third-party dependencies.  In our case, we are concerned with using vulnerable versions of Log4j.

Utilize CodeSec by Contrast to secure those vulnerable libraries by running the command: contrast audit

Contrast Audit

As described, this simple command from CodeSec detected the vulnerable versions of Log4j defined in our project. Additionally, it lists the specific vulnerability codes (which we could look up in the NIST NVD database for more details), and it gives advice on how to make the project more secure by upgrading the versions of Log4j used.

Contrast Security also has an entire online portal dedicated to the Log4j vulnerability problem.  There you can find more resources, whitepapers and information about all the other tools Contrast Security offers for detecting, handling, and remediating your Log4j vulnerability risks.



CodeSec gives developers an expert tool that handles the chores of searching Java projects and detecting Log4j vulnerabilities and other exploits while staying up to date on the latest developments in cybersecurity research.  It is a highly valuable and free utility that can improve a team’s software development practices.

Jacob Mages-Haskins, Staff Software Engineer, Contrast Security

Jacob Mages-Haskins, Staff Software Engineer, Contrast Security

Jacob is a software engineer with decades of experience. He lives in New England with his family and enjoys reading, gardening and the outdoors.