Denial of Service (DoS)

Affecting rack gem, versions >=2.0.4, <2.0.6

medium severity

Overview

rack provides a minimal, modular and adaptable interface for developing web applications in Ruby.

Affected versions of this package are vulnerable to Denial of Service (DoS) attacks. Carefully crafted requests can cause the multipart parser to enter a pathological state, causing the parser to use CPU resources disproportionate to the request size.

details

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

Remediation

Upgrade rack to version 2.0.6 or higher.

References

Do your applications use this vulnerable package?

Credit
Aaron Patterson
CVE
CVE-2018-16471
CWE
CWE-400
Snyk ID
SNYK-RUBY-RACK-72566
Disclosed
22 Aug, 2018
Published
06 Nov, 2018