CVE-2019-16255

Name: CVE-2019-16255
Creator: NVD / NIST
Published: 2019-11-26T18:15:15.303+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.1/10EPSS 4.22%

Last modified Jun 17, 2026

CVE-2019-16255 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. Ruby through 2.4.7, 2.5.x through 2.5.6, and 2.6.x through 2.6.4 allows code injection if the first argument (aka the "command" argument) to Shell#[] or Shell#test in lib/shell.rb is untrusted data. An attacker can exploit this to call an arbitrary Ruby method.. EPSS estimates a 4.22% chance of exploitation in the next 30 days.

Description

Ruby through 2.4.7, 2.5.x through 2.5.6, and 2.6.x through 2.6.4 allows code injection if the first argument (aka the "command" argument) to Shell#[] or Shell#test in lib/shell.rb is untrusted data. An attacker can exploit this to call an arbitrary Ruby method.

Metrics

CVSS 3.1

8.1/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

4.22%

89.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-94

Affected Software

Vendor	Product	Versions
Ruby-Lang	Ruby	>= 2.4.0, <= 2.4.7
Ruby-Lang	Ruby	>= 2.5.0, <= 2.5.6
Ruby-Lang	Ruby	>= 2.6.0, <= 2.6.4
Debian	Debian Linux	8.0
Debian	Debian Linux	9.0
Opensuse	Leap	15.1
Oracle	Graalvm	19.3.0.2

References

http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00041.htmlThird Party Advisory
https://hackerone.com/reports/327512Exploit, Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/11/msg00025.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/12/msg00009.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/08/msg00027.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html
https://seclists.org/bugtraq/2019/Dec/31Broken Link, Mailing List, Third Party Advisory
https://seclists.org/bugtraq/2019/Dec/32Broken Link, Mailing List, Third Party Advisory
https://security.gentoo.org/glsa/202003-06Third Party Advisory
https://www.debian.org/security/2019/dsa-4587Third Party Advisory
https://www.oracle.com/security-alerts/cpujan2020.htmlPatch, Third Party Advisory
https://www.ruby-lang.org/ja/news/2019/10/01/code-injection-shell-test-cve-2019-16255/Vendor Advisory
https://www.ruby-lang.org/ja/news/2019/10/01/ruby-2-4-8-released/Release Notes
https://www.ruby-lang.org/ja/news/2019/10/01/ruby-2-5-7-released/Release Notes
https://www.ruby-lang.org/ja/news/2019/10/01/ruby-2-6-5-released/Release Notes
http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00041.htmlThird Party Advisory
https://hackerone.com/reports/327512Exploit, Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/11/msg00025.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/12/msg00009.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/08/msg00027.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html
https://seclists.org/bugtraq/2019/Dec/31Broken Link, Mailing List, Third Party Advisory
https://seclists.org/bugtraq/2019/Dec/32Broken Link, Mailing List, Third Party Advisory
https://security.gentoo.org/glsa/202003-06Third Party Advisory
https://www.debian.org/security/2019/dsa-4587Third Party Advisory
https://www.oracle.com/security-alerts/cpujan2020.htmlPatch, Third Party Advisory
https://www.ruby-lang.org/ja/news/2019/10/01/code-injection-shell-test-cve-2019-16255/Vendor Advisory
https://www.ruby-lang.org/ja/news/2019/10/01/ruby-2-4-8-released/Release Notes
https://www.ruby-lang.org/ja/news/2019/10/01/ruby-2-5-7-released/Release Notes
https://www.ruby-lang.org/ja/news/2019/10/01/ruby-2-6-5-released/Release Notes

Timeline

Published: Nov 26, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-16255?

How severe is CVE-2019-16255?

CVE-2019-16255 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 4.22% probability of exploitation in the next 30 days.

How do I fix CVE-2019-16255?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-16255?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST