Red 73 (React CVE-2025-55182)

                                                    [<https://cyberlessons101.com>](<https://cyberlessons101.com>)

docker run -d --name flag-red73 --restart always -p 10001:3000 joshbeck2024/ctf-react-cve-2025-55182

For the average user, the React Flight Protocol is essentially a "high-speed delivery service" for websites.
In the past, when you clicked a link, your browser would download everything needed and then build the entire page, which made sites feel heavy or slow on mobile. With the Flight Protocol:
- Instant Content: The server does the heavy lifting of "building" the page and streams the finished pieces to your browser immediately.
- Smoother Experience: It allows parts of a page to update—like a "Like" count or a comment—without the whole screen blinking or refreshing.
- Faster Loading: Because the browser doesn't have to download nearly as much code, the website loads faster and uses less battery and data on your phone.

(Calculating CVSS scores is a key Sec+ Concept/Skill)

Unauthenticated Remote Access: An attacker does not need a username, password, or any special permissions.
Zero User Interaction: Unlike phishing (where a user must click a link) or other bugs that require a user to perform an action, this exploit triggers automatically when the server processes a malicious request.
Low Attack Complexity: (Lots of pre-made exploits!) A single, well-crafted HTTP POST request is often enough.
Default Configuration Risk: You don't have to "mess up" your settings to be vulnerable. If you are using standard React 19 or Next.js 15+ with the App Router, the "vulnerable code" is enabled and exposed by default.
Total Integrity and Confidentiality Loss: Once the exploit succeeds, the attacker has full "Remote Code Execution" (RCE). They can read every file on the server (Confidentiality) and change or delete any data (Integrity.)

The scale of exposure for CVE-2025-55182 was massive upon its disclosure in late 2025. Here is a breakdown of the detection data:

Censys: 2.15 Million Detections Total internet-facing instances identified using frameworks like Next.js that were potentially affected by the vulnerability.