Webpack version 4.35.0, released on June 20, 2019, builds upon the previous stable version 4.34.0, released just a week earlier on June 12, 2019. Both versions serve the core purpose of packing CommonJs/AMD modules for browser deployment and facilitating codebase splitting into smaller, on-demand loaded bundles. They share identical dependencies like ajv, acorn, tapable, and webpack-sources, and developer dependencies such as eslint, jest, react, and various loaders (css, less, pug, etc.). This implies a consistent set of core functionalities and a continued commitment to supporting a well-defined ecosystem for module bundling and front-end development.
The key difference lies in the internal improvements and bug fixes that likely drove the minor version bump. The unpackedSize for 4.35.0 is marginally larger (1398027 bytes) compared to 4.34.0 (1393872 bytes) suggesting that the update introduced some additional code, potentially to address identified issues or optimize existing features. While the package metadata doesn't explicitly detail the specific changes, developers upgrading from 4.34.0 to 4.35.0 could expect slightly improved stability or performance. For developers, it is generally recommended to upgrade to the latest stable version to benefit from the cumulative fixes and enhancements baked into each release.
All the vulnerabilities related to the version 4.35.0 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.
