Denial of Service (DoS)

Affecting rendertron-middleware package, versions <0.1.3

high severity


rendertron-middleware is an Express middleware for Rendertron.

Affected versions of this package are vulnerable to Denial of Service (DoS). It included an _ah/stop route to shutdown the Chrome instance responsible for serving render requests to all users. Visiting this route with a GET request allowed any unauthorized remote attacker to disable the core service of the application.


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


Upgrade rendertron-middleware to version 0.1.3 or higher.


Do your applications use this vulnerable package?

Snyk ID
17 Dec, 2018
18 Dec, 2018