Webpack 4.42.0, released on March 2nd, 2020, offers a subtle yet potentially impactful update compared to its predecessor, version 4.41.6, released on February 11th, 2020. While the core functionality remains consistent, developers should note distinctions primarily in file count and package size within the distribution. Version 4.42.0 incorporates 358 files, modestly increasing the unpacked size to 1,465,649 bytes, whereas version 4.41.6 comprised 357 files with an unpacked size of 1,465,431 bytes. These small changes suggest minor internal adjustments, bug fixes, or optimizations within the build process.
For those leveraging the webpack library, this update likely translates to improved stability and potentially enhanced performance, however, a very minor update will not deliver substantial changes. Considering the widespread use of webpack in modern JavaScript development, any incremental improvement is valuable. It is important to note that both versions share identical dependency and devDependencies lists, indicating that the core ecosystem and supporting tools remain aligned. Developers should prioritize testing when upgrading to 4.42.0, particularly in complex configurations, to ensure seamless integration with existing projects. The updates, while subtle, aim to refine the bundler's operation, maintaining its position as a go-to tool for managing and optimizing web application assets.
All the vulnerabilities related to the version 4.42.0 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.
