Sass version 1.21.0 represents a subtle yet noteworthy update over its predecessor, version 1.20.3. Both versions share the same core description, functioning as pure JavaScript implementations of Sass, showcasing their commitment to accessibility and integration within JavaScript-centric workflows. They also maintain identical dependency on chokidar for file system watching capabilities, a crucial feature for developers looking for automated Sass compilation during development. The licensing remains consistent under the MIT license, assuring flexibility for usage in a wide array of projects, and the repository and author information are unchanged, indicating sustained maintenance and commitment from the core team.
The most evident distinction lies in the jump from version 1.20.3 to 1.21.0, signalling bug fixes, performance improvements, or minor feature enhancements rather than a major overhaul. The unpacked size of 1.21.0 is slightly larger, indicating the addition of new code or assets. Developers should also note the release dates: version 1.21.0 was released on June 6, 2019, shortly after version 1.20.3 on May 31, 2019, suggesting a quick follow-up update. While the core functionality remains consistent, upgrading to 1.21.0 offers developers access to any resolved issues or refinements implemented since 1.20.3, contributing to a potentially more stable and efficient Sass compilation process, especially beneficial for larger projects that benefit significantly from even minor improvements. Developers should consult the official changelog for a detailed breakdown of specific changes.
All the vulnerabilities related to the version 1.21.0 of the package
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.
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.
