CVE-2025-30359: webpack webpack-dev-server Exposed Dangerous Method or Function

Vulnerability summary

CVE-2025-30359 is a medium (CVSS 5.9) Exposed Dangerous Method or Function vulnerability in webpack webpack-dev-server. EPSS estimates a 0.57% chance of exploitation in the next 30 days, higher than 46.5% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 03-06-2025
   PublishedVulnerability first disclosed.
2. 03-06-2025
   Last modifiedVulnerability information updated.

Description

webpack-dev-server allows users to use webpack with a development server that provides live reloading. Prior to version 5.2.1, webpack-dev-server users' source code may be stolen when they access a malicious web site. Because the request for classic script by a script tag is not subject to same origin policy, an attacker can inject a malicious script in their site and run the script. Note that the attacker has to know the port and the output entrypoint script path. Combined with prototype pollution, the attacker can get a reference to the webpack runtime variables. By using `Function::toString` against the values in `__webpack_modules__`, the attacker can get the source code. Version 5.2.1 contains a patch for the issue.

• CWE-749Exposed Dangerous Method or FunctionThe product provides an Applications Programming Interface (API) or similar interface for interaction with external actors, but the interface includes a dangerous method or function that is not properly restricted.