Denial of Service (DoS) Affecting package, versions <2.0.2

  • Exploit Maturity

    Proof of concept

  • Attack Complexity


  • Availability


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  • snyk-id


  • published

    3 Jun 2020

  • disclosed

    23 Jul 2019

  • credit

    Aviv Sasson from Twistlock Security Team

How to fix?

Upgrade to version 2.0.2 or higher.

Overview is an A simple, secure and performant communications system for digital systems, services and devices.

Affected versions of this package are vulnerable to Denial of Service (DoS). As a user, you can send a publish request which will publish a message to a subject, and all of the clients who are subscribed to the subject will receive the message. The problem is that the go runtime function make treats the capacity parameter as an unsigned int so instead of a negative number, it treats it like the number we sent it and then it tries to allocate an abnormal slice and panics.


Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

  • High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

  • Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package