Description
An issue was discovered in HMRServer.js in Parcel parcel-bundler. Attackers are able to steal developer's code because the origin of requests is not checked by the WebSocket server, which is used for HMR (Hot Module Replacement). Anyone can receive the HMR message sent by the WebSocket server via a ws://127.0.0.1 connection (with a random TCP port number) from any origin. The random port number can be found by connecting to http://127.0.0.1 and reading the "new WebSocket" line in the source code.
Remediation
References
https://blog.cal1.cn/post/Sniffing%20Codes%20in%20Hot%20Module%20Reloading%20Messages
https://github.com/parcel-bundler/parcel/issues/1783
https://github.com/parcel-bundler/parcel/pull/1794
Related Vulnerabilities
CVE-2020-13921 Vulnerability in maven package org.apache.skywalking:storage-jdbc-hikaricp-plugin
CVE-2018-3721 Vulnerability in npm package @sailshq/lodash
CVE-2020-13943 Vulnerability in maven package org.apache.tomcat.embed:tomcat-embed-core
CVE-2020-15171 Vulnerability in maven package org.xwiki.platform:xwiki-platform-oldcore