A brand new safety evaluation software has been launched to assist researchers and directors determine React Server Elements (RSC) endpoints doubtlessly uncovered to CVE-2025-55182.
Developed as a light-weight by Pentester with the alias Fatguru, a non-intrusive Python script, the scanner affords a technique for “Floor Detection” that avoids the pitfalls of aggressive proof-of-concept (PoC) exploits, which continuously fail in manufacturing environments as a result of code minification and tree-shaking.
CVE-2025-55182 is a essential vulnerability within the Subsequent.js framework, particularly affecting how Server Actions deal with serialized knowledge. Whereas the vulnerability can result in Distant Code Execution (RCE), verifying its presence has confirmed troublesome for safety groups.
Many current PoCs try and inject inflexible payloads, comparable to vm#runInThisContext, or depend on default module IDs like {“id”:”vm”}.
In growth environments, these payloads typically set off efficiently. Nevertheless, in manufacturing builds utilizing Webpack or Turbopack, module IDs are usually minified into integers (e.g., 742) or quick strings.
Consequently, commonplace RCE makes an attempt fail in opposition to susceptible servers as a result of the exploit payload references module names that now not exist within the compiled code, resulting in a harmful false sense of safety.
The newly launched scanner addresses this detection hole by validating the assault floor reasonably than making an attempt to fireplace a selected exploit gadget.
As a substitute of sending a malicious payload, the software checks if the goal server exposes the RSC protocol indicated by the Content material-Sort: textual content/x-component header and accepts particular Subsequent.js motion headers. If the server makes an attempt to course of these RSC payloads, the software flags the endpoint as uncovered.
This strategy confirms that the vulnerability pathway is open with no need to guess the proper minified module ID or disrupt the server operations.
For safety professionals, a optimistic outcome from this scanner signifies that the endpoint is reachable and processing doubtlessly harmful enter.
The software’s documentation notes that if the scanner flags a goal, additional handbook validation is required to show RCE. This may contain enumerating or fuzzing the Webpack Module ID (typically integers between 1 and 5000 in manufacturing) or analyzing client-side belongings like webpack-runtime.js to map legitimate IDs to potential devices.
The software is designed for ease of use and integration into current workflows. It helps single-target scanning through command line arguments in addition to bulk scanning by means of record enter, outputting outcomes to a CSV file for reporting. Stipulations for operating the software are minimal, requiring solely Python 3 and commonplace library dependencies.
This launch supplies a vital functionality for organizations operating Subsequent.js purposes, permitting them to audit their publicity to CVE-2025-55182 successfully earlier than attackers can reverse-engineer manufacturing builds to craft working exploits.
Remediation Steps:
Improve Instantly: Replace to the newest patched variations (e.g., Subsequent.js 15.0.5+, 15.1.9+, or 16.0.7+).
Confirm Publicity: Use the scanner to audit your exterior assault floor and ensure that no unpatched endpoints stay accessible.
Obtain the Software: Safety groups can entry the scanner and full documentation on the official repository under.
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