Impact: When a user-configured proxy on webpack-dev-server has a broad context (e.g. /) and ws: true, it also intercepts the dev servers own HMR WebSocket and forwards it to the proxy target. This leaks the browsers cookies and Origin header to the backend, bypasses the dev servers Host/Origin validation, and corrupts the HMR socket (both HMR and the proxy end up writing to the same socket).
Patches: Fixed in webpack-dev-server@5.2.5.
Workarounds: Scope user-defined proxy context to specific paths instead of /, or omit ws: true from the proxy entry when WebSocket forwarding is not required.
Weakness
The product does not properly verify that the source of data or communication is valid.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Webpack-dev-server | Webpack.js | * | 5.2.5 (excluding) |
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/111.html
- https://cwe.mitre.org/data/definitions/141.html
- https://cwe.mitre.org/data/definitions/142.html
- https://cwe.mitre.org/data/definitions/160.html
- https://cwe.mitre.org/data/definitions/21.html
- https://cwe.mitre.org/data/definitions/384.html
- https://cwe.mitre.org/data/definitions/385.html
- https://cwe.mitre.org/data/definitions/386.html
- https://cwe.mitre.org/data/definitions/387.html
- https://cwe.mitre.org/data/definitions/388.html
- https://cwe.mitre.org/data/definitions/510.html
- https://cwe.mitre.org/data/definitions/59.html
- https://cwe.mitre.org/data/definitions/60.html
- https://cwe.mitre.org/data/definitions/75.html
- https://cwe.mitre.org/data/definitions/76.html
- https://cwe.mitre.org/data/definitions/89.html
References
- https://cna.openjsf.org/security-advisories.html
- https://github.com/facebook/create-react-app/pull/7444
- https://github.com/vuejs/vue-cli/commit/72ba7505aff2a8314e82aa5082379a77504a1fcb
- https://github.com/webpack/webpack-dev-server/pull/4316
- https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-mx8g-39q3-5c79