Webpack version 4.42.1 arrived on March 24, 2020, shortly after version 4.42.0 released on March 2, 2020. Both versions serve the same core purpose: bundling CommonJs/AMD modules for browsers, enabling code splitting and on-demand loading, and supporting loaders for diverse file types.
A detailed comparison reveals subtle but potentially important changes. In dependencies, version 4.42.1 upgrades @webassemblyjs components (ast, wasm-edit, wasm-parser, and helper-module-context) to version 1.9.0. Version 4.42.0 used version 1.8.5. mkdirp was upgraded from version 0.5.1 to version 0.5.3. This indicates improvements or bug fixes in WebAssembly handling and directory creation within the newer version.
While the devDependencies are largely identical, the core libraries crucial for webpack's functionality show targeted updates. Developers working with WebAssembly should specifically note the upgrade to @webassemblyjs libraries, as it might impact compatibility or unlock new features. The dist information, showing a slight change in unpackedSize (1465685 vs 1465649), implies that the newer 4.42.1 introduces code adjustments, which aligns with the dependency updates. Therefore, upgrading to 4.42.1 is advised for projects leveraging WebAssembly or relying on mkdirp for enhanced stability and access to the latest features and fixes within those dependencies. It is also useful as this change can involve some security fixes.
All the vulnerabilities related to the version 4.42.1 of the package
Regular Expression Denial of Service (ReDoS) in micromatch
The NPM package micromatch prior to version 4.0.8 is vulnerable to Regular Expression Denial of Service (ReDoS). The vulnerability occurs in micromatch.braces() in index.js because the pattern .* will greedily match anything. By passing a malicious payload, the pattern matching will keep backtracking to the input while it doesn't find the closing bracket. As the input size increases, the consumption time will also increase until it causes the application to hang or slow down. There was a merged fix but further testing shows the issue persisted prior to https://github.com/micromatch/micromatch/pull/266. This issue should be mitigated by using a safe pattern that won't start backtracking the regular expression due to greedy matching.
Uncontrolled resource consumption in braces
The NPM package braces fails to limit the number of characters it can handle, which could lead to Memory Exhaustion. In lib/parse.js, if a malicious user sends "imbalanced braces" as input, the parsing will enter a loop, which will cause the program to start allocating heap memory without freeing it at any moment of the loop. Eventually, the JavaScript heap limit is reached, and the program will crash.
