thinQtankLABS

Detection Engineering & Incident Response: CVE-2025-55182

Respond to a React Server Components deserialization-RCE compromise (CVE-2025-55182). Reconstruct the timeline from the access and execution logs, see how a server-action payload resolved an arbitrary reference and ran as the node process, find the dropped-script persistence, engineer a detection rule for the malicious payload marker, then contain, eradicate, upgrade, verify and report.

Intermediate 20 guided steps 6 tasks About 75 minutes Runs in your browser

Skills you will practice

  • Log analysis
  • detection and IR; Incident-handling lifecycle; Deserialization attacks and IOCs; Security Operations domain

Certifications this lab maps to

This lab builds hands-on skills that appear on these certification exams. thinQtank Learning runs instructor-led training camps for each — click one to see upcoming classes.

CompTIA CySA+ CS0-003 Log analysis, detection and IR Training at thinQtank Learning EC-Council Certified Incident Handler E|CIH Incident-handling lifecycle Training at thinQtank Learning EC-Council Certified Ethical Hacker CEH Deserialization attacks and IOCs Training at thinQtank Learning ISC2 CISSP CISSP Security Operations domain Training at thinQtank Learning
Part of these certification lab packages: CySA+ CS0-003 CISSP Certified Ethical Hacker (CEH) CEH Certified Incident Handler (E|CIH) E|CIH GCIH GCIH GCIA GCIA

The scenario

A public React app (CVE-2025-55182 open) logged unauthenticated server-action requests whose payloads reference arbitrary code, then the node process spawned a shell. You are the responder. Classify it.

What you will do

  1. Open and classify the incident4 steps

    Open the incident · Read the alert · Read the ticket · Classify it

  2. Reconstruct the timeline3 steps

    Pull the attacker’s requests · Correlate the execution log · What made RCE possible?

  3. Impact and persistence3 steps

    Inspect the dropped file · What persistence? · Record IOCs

  4. Engineer a detection rule4 steps

    Study the sample · Write a rule · Test and tune · Why not flag every action?

  5. Contain, eradicate, verify4 steps

    Eradicate the dropped script · Upgrade the package · Verify the host · Confirm detection holds

  6. Report2 steps

    Write the report · Root fix vs patch

How this lab works

A real Linux-style console. Commands run against real files, so hashes, hex dumps and comparisons give real results.

A file browser where you can place evidence into the lab, either the file provided or one of your own.

Reset a single step, a whole task or the entire lab. The environment is rebuilt so you can try again cleanly.

Progress saves after every step. Close the tab and come back later; your files and answers are waiting.