Angular Expressions - Remote Code Execution using filters

Impact

An attacker can write a malicious expression that escapes the sandbox to execute arbitrary code on the system.

Example of vulnerable code:

const expressions = require("angular-expressions");
const result = expressions.compile("a | __proto__")({}, {});

This should throw the error : Filter 'proto' is not defined, however, this shows :

Uncaught SyntaxError: Unexpected identifier 'Object'

With a more complex (undisclosed) payload, one can get full access to Arbitrary code execution on the system.

Vulnerable versions :

angular-expressions <= 1.5.1

Patches

The problem has been patched in version 1.5.2 of angular-expressions.

Credits

Credits go to San Gil from www.securityoffice.io who has found the issue and reported it to us.