Ruby Multiple Security Vulnerabilities



Date Discovered

October 1, 2019


Ruby is prone to the following security vulnerabilities: 1. An authorization-bypass vulnerability 2. A denial-of-service vulnerability 3. An HTTP response-splitting vulnerability 4. A command-injection vulnerability An attacker can exploit these issues to bypass certain security restrictions and perform unauthorized actions, execute arbitrary commands, influence or misrepresent how web content is served, cached, and interpreted or cause excessive CPU resource consumption, resulting in denial-of-service conditions. The following products are affected: Ruby 2.3 and prior versions Ruby 2.4 versions prior to 2.4.7 Ruby 2.5 versions prior to 2.5.6 Ruby 2.6 versions prior to 2.6.4 Ruby 2.7.0-preview1

Technologies Affected

  • Ruby-Lang Ruby 1.8
  • Ruby-Lang Ruby 1.8.5
  • Ruby-Lang Ruby 1.8.7
  • Ruby-Lang Ruby 1.9
  • Ruby-Lang Ruby 1.9.0
  • Ruby-Lang Ruby 1.9.1
  • Ruby-Lang Ruby 1.9.2
  • Ruby-Lang Ruby 1.9.3
  • Ruby-Lang Ruby 2.1.2
  • Ruby-Lang Ruby 2.1.3
  • Ruby-Lang Ruby 2.1.4
  • Ruby-Lang Ruby 2.1.5
  • Ruby-Lang Ruby 2.1.6
  • Ruby-Lang Ruby 2.2.0
  • Ruby-Lang Ruby 2.3.0
  • Ruby-Lang Ruby 2.3.1
  • Ruby-Lang Ruby 2.3.4
  • Ruby-Lang Ruby 2.3.5
  • Ruby-Lang Ruby 2.3.6
  • Ruby-Lang Ruby 2.3.7
  • Ruby-Lang Ruby 2.3.8
  • Ruby-Lang Ruby 2.4.0
  • Ruby-Lang Ruby 2.4.1
  • Ruby-Lang Ruby 2.4.2
  • Ruby-Lang Ruby 2.4.3
  • Ruby-Lang Ruby 2.4.4
  • Ruby-Lang Ruby 2.4.5
  • Ruby-Lang Ruby 2.4.6
  • Ruby-Lang Ruby 2.5.0
  • Ruby-Lang Ruby 2.5.1
  • Ruby-Lang Ruby 2.5.2
  • Ruby-Lang Ruby 2.5.5
  • Ruby-Lang Ruby 2.6
  • Ruby-Lang Ruby 2.6.3
  • Ruby-Lang Ruby 2.7.0-preview1
  • Ubuntu Ubuntu Linux 16.04 LTS
  • Ubuntu Ubuntu Linux 18.04 LTS
  • Ubuntu Ubuntu Linux 19.04
  • Ubuntu Ubuntu Linux 19.10


Block external access at the network boundary, unless external parties require service.
Filter access to the affected computer at the network boundary if global access isn't needed. Restricting access to only trusted computers and networks might greatly reduce the likelihood of a successful exploit.

Run all software as a nonprivileged user with minimal access rights.
When possible, run all software as a user with minimal privileges and limited access to system resources. Use additional precautions such as restrictive environments to insulate software that may potentially handle malicious content.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of anomalous or suspicious activity including unexplained incoming and outgoing traffic. This may indicate exploit attempts or activity that results from successful exploits.

Do not follow links provided by unknown or untrusted sources.
Web users should be cautious about following links to sites that are provided by unfamiliar or suspicious sources. Filtering HTML from emails may help remove a possible vector for transmitting malicious links to users.

Updates are available. Please see the references or vendor advisory for more information.



ooooooo_q (ooooooo_q), ceh (358) and Kazuhiro NISHIYAMA (znz).

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