CVE-2021-21277

### Impact The vulnerability, reported by GoSecure Inc, allows Remote Code Execution, if you call `expressions.compile(userControlledInput)` where `userControlledInput` is text that comes from user input. This time, the security of the package could be bypassed by using a more complex payload, using a `.constructor.constructor` technique. * If running angular-expressions in the browser, an attacker could run any browser script when the application code calls expressions.compile(userControlledInput). * If running angular-expressions on the server, an attacker could run any Javascript expression, thus gaining Remote Code Execution. ### Patches Users should upgrade to version 1.1.2 of angular-expressions ### Workarounds A temporary workaround might be either to : * disable user-controlled input that will be fed into angular-expressions in your application OR * allow only following characters in the userControlledInput : ```js if (/^[|a-zA-Z.0-9 :"'+-?]+$/.test(userControlledInput)) { var result = expressions.compile(userControlledInput); } else { result = undefined; } ``` ### References [Removal of angular-expression sandbox](http://blog.angularjs.org/2016/09/angular-16-expression-sandbox-removal.html) ### For more information If you have any questions or comments about this advisory: * Open an issue in [angular-expressions](https://github.com/peerigon/angular-expressions/issues) * [Email us](mailto:contact@javascript-ninja.fr) ### Credits The issue was reported by Maxime Nadeau from GoSecure, Inc.