Sass version 1.9.1 represents a minor update to the popular Dart Sass library, building upon the foundation established by version 1.9.0. Both versions offer developers a pure JavaScript implementation of the Sass stylesheet language, enabling seamless integration into JavaScript-based projects without requiring native dependencies. This is a significant advantage, simplifying cross-platform development and deployment. Crucially, both versions rely on the same dependency, chokidar (version 2.0.0 or higher), for file system watching. This indicates that the core mechanism for automatically recompiling Sass files upon changes remains consistent between the two versions.
The key difference lies in the subtle adjustments to the codebase, reflected in a marginally increased unpacked size for version 1.9.1 (688306 bytes) compared to 1.9.0 (688190 bytes). This small increment suggests bug fixes, performance enhancements, or minor feature additions rather than a major overhaul. Developers should likely consider upgrading to 1.9.1 for improved stability and potential performance gains. The release date difference also indicates a fairly rapid turnaround between versions, demonstrating active maintenance and responsiveness from the Sass team. Both versions are licensed under the MIT license, granting developers broad freedom in their use. For those seeking a reliable and actively maintained JavaScript Sass compiler, either version is a viable option, with 1.9.1 representing the slightly more refined choice.
All the vulnerabilities related to the version 1.9.1 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.
