Babel-loader versions 6.2.6 and 6.2.5 represent incremental updates to a crucial tool for integrating Babel with Webpack, enabling developers to transpile modern JavaScript code for broader browser compatibility. While both versions share core functionality – loading Babel modules for Webpack, utilizing dependencies like mkdirp and loader-utils, and sporting similar development dependencies for linting, testing, and code coverage – key distinctions exist. Version 6.2.6 introduces the find-cache-dir dependency, potentially enhancing performance through smarter cache directory management, a boon for faster builds. Both versions maintain peer dependency requirements for webpack (version 1 or newer, supporting beta versions of 2.1.0) and babel-core (version 6 and above), ensuring compatibility with widely-used setups.
The update from 6.2.5 to 6.2.6 includes a bump in jscs and mocha development dependencies to ^3.0.7 and ^3.0.2 respectively, suggesting improvements in code style checking and testing frameworks. No new dependencies were introduced between 6.2.5 and 6.2.6, which is good because it means there should not be any new security vulnerability, potential breaking changes or licensing implications between the 2 versions. The release date difference indicates a couple of months of development time between versions, suggesting bug fixes or small improvements. Developers should evaluate the potential benefits of find-cache-dir in 6.2.6 against the stability of their existing 6.2.5 setup. If better performances is not important, then it's recommended to stay with already tested version.
All the vulnerabilities related to the version 6.2.6 of the package
Prototype pollution in webpack loader-utils
Prototype pollution vulnerability in function parseQuery in parseQuery.js in webpack loader-utils prior to version 2.0.3 via the name variable in parseQuery.js.
Prototype Pollution in JSON5 via Parse Method
The parse method of the JSON5 library before and including version 2.2.1 does not restrict parsing of keys named __proto__, allowing specially crafted strings to pollute the prototype of the resulting object.
This vulnerability pollutes the prototype of the object returned by JSON5.parse and not the global Object prototype, which is the commonly understood definition of Prototype Pollution. However, polluting the prototype of a single object can have significant security impact for an application if the object is later used in trusted operations.
This vulnerability could allow an attacker to set arbitrary and unexpected keys on the object returned from JSON5.parse. The actual impact will depend on how applications utilize the returned object and how they filter unwanted keys, but could include denial of service, cross-site scripting, elevation of privilege, and in extreme cases, remote code execution.
This vulnerability is patched in json5 v2.2.2 and later. A patch has also been backported for json5 v1 in versions v1.0.2 and later.
Suppose a developer wants to allow users and admins to perform some risky operation, but they want to restrict what non-admins can do. To accomplish this, they accept a JSON blob from the user, parse it using JSON5.parse, confirm that the provided data does not set some sensitive keys, and then performs the risky operation using the validated data:
const JSON5 = require('json5');
const doSomethingDangerous = (props) => {
if (props.isAdmin) {
console.log('Doing dangerous thing as admin.');
} else {
console.log('Doing dangerous thing as user.');
}
};
const secCheckKeysSet = (obj, searchKeys) => {
let searchKeyFound = false;
Object.keys(obj).forEach((key) => {
if (searchKeys.indexOf(key) > -1) {
searchKeyFound = true;
}
});
return searchKeyFound;
};
const props = JSON5.parse('{"foo": "bar"}');
if (!secCheckKeysSet(props, ['isAdmin', 'isMod'])) {
doSomethingDangerous(props); // "Doing dangerous thing as user."
} else {
throw new Error('Forbidden...');
}
If the user attempts to set the isAdmin key, their request will be rejected:
const props = JSON5.parse('{"foo": "bar", "isAdmin": true}');
if (!secCheckKeysSet(props, ['isAdmin', 'isMod'])) {
doSomethingDangerous(props);
} else {
throw new Error('Forbidden...'); // Error: Forbidden...
}
However, users can instead set the __proto__ key to {"isAdmin": true}. JSON5 will parse this key and will set the isAdmin key on the prototype of the returned object, allowing the user to bypass the security check and run their request as an admin:
const props = JSON5.parse('{"foo": "bar", "__proto__": {"isAdmin": true}}');
if (!secCheckKeysSet(props, ['isAdmin', 'isMod'])) {
doSomethingDangerous(props); // "Doing dangerous thing as admin."
} else {
throw new Error('Forbidden...');
}