Webpack is a module bundler. Its main purpose is to bundle JavaScript files for usage in a browser, yet it is also capable of transforming, bundling, or packaging just about any resource or asset. The webpack developers have discovered a DOM Clobbering vulnerability in Webpack’s `AutoPublicPathRuntimeModule`. The DOM Clobbering gadget in the module can lead to cross-site scripting (XSS) in web pages where scriptless attacker-controlled HTML elements (e.g., an `img` tag with an unsanitized `name` attribute) are present. Real-world exploitation of this gadget has been observed in the Canvas LMS which allows a XSS attack to happen through a javascript code compiled by Webpack (the vulnerable part is from Webpack). DOM Clobbering is a type of code-reuse attack where the attacker first embeds a piece of non-script, seemingly benign HTML markups in the webpage (e.g. through a post or comment) and leverages the gadgets (pieces of js code) living in the existing javascript code to transform i…

Prior to versions 7.1.0, 6.1.2, and 5.3.4, the webpack-dev-middleware development middleware for devpack does not validate the supplied URL address sufficiently before returning the local file. It is possible to access any file on the developer's machine. The middleware can either work with the physical filesystem when reading the files or it can use a virtualized in-memory `memfs` filesystem. If `writeToDisk` configuration option is set to `true`, the physical filesystem is used. The `getFilenameFromUrl` method is used to parse URL and build the local file path. The public path prefix is stripped from the URL, and the `unsecaped` path suffix is appended to the `outputPath`. As the URL is not unescaped and normalized automatically before calling the midlleware, it is possible to use `%2e` and `%2f` sequences to perform path traversal attack. Developers using `webpack-dev-server` or `webpack-dev-middleware` are affected by the issue. When the project is started, an attacker might acce…

Webpack 5 before 5.76.0 does not avoid cross-realm object access. ImportParserPlugin.js mishandles the magic comment feature. An attacker who controls a property of an untrusted object can obtain access to the real global object.

Directory Traversal vulnerability in easywebpack-cli before 4.5.2 allows attackers to obtain sensitive information via crafted GET request.

In webpack-subresource-integrity before version 1.5.1, all dynamically loaded chunks receive an invalid integrity hash that is ignored by the browser, and therefore the browser cannot validate their integrity. This removes the additional level of protection offered by SRI for such chunks. Top-level chunks are unaffected. This issue is patched in version 1.5.1.

An issue was discovered in lib/Server.js in webpack-dev-server before 3.1.6. 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://127.0.0.1:8080/ connection from any origin.