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CVE-2019-16255

27
FAUCET Score

CVE-2019-16255 describes a code injection vulnerability in Ruby versions 2.4.7, 2.5.6, and 2.6.4 and earlier, specifically within the Shell#[] or Shell#test methods if untrusted data is passed as the command argument. This critical flaw, affecting distributions like Debian, OpenSUSE, and Oracle, allows an unauthenticated attacker to execute arbitrary Ruby methods remotely with high impact on confidentiality, integrity, and availability. Despite its high CVSS score of 8.1 and significant potential, there is currently no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or notable community discussion or media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
>= 2.4.0, <= 2.4.7CPE matchmatch criteria
cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
>= 2.5.0, <= 2.5.6CPE matchmatch criteria
cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
>= 2.6.0, <= 2.6.4CPE matchmatch criteria
cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
8.0CPE matchmatch criteria
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
9.0CPE matchmatch criteria
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

8.1HIGH

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

Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
2.2
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
4.19%
Probability of exploitation in next 30 days
EPSS Percentile
89.9%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0419 is in the 54th percentile among its peer group of 8,920 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (17)

microsoftpatch availablevia msrc
Product: cm1 ruby 2.6.7-1 on CBL Mariner 1.0Fixed in: 2.6.7-1
microsoftpatch availablevia msrc
Product: 17016-16820Fixed in: 2.6.7-1
microsoftpatch availablevia msrc
Product: CBL Mariner 1.0 ARMFixed in: 2.6.7-1
microsoftpatch availablevia msrc
Product: CBL Mariner 1.0 x64Fixed in: 2.6.7-1
oraclepatch availablevia nvd_reference
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.2 Extended Update SupportFixed in: ruby:2.6-8020020220201131207.4cda2c84
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: rh-ruby25-ruby-0:2.5.9-9.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: rh-ruby26-ruby-0:2.6.7-119.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUSFixed in: rh-ruby25-ruby-0:2.5.9-9.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUSFixed in: rh-ruby25-ruby-0:2.5.9-9.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUSFixed in: rh-ruby26-ruby-0:2.6.7-119.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.1 Update Services for SAP SolutionsFixed in: ruby:2.6-8010020220201152941.c27ad7f8
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: ruby:2.6-8040020210430142949.522a0ee4
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: ruby:2.5-8040020200923213910.522a0ee4
View patch
redhatend of lifevia redhat_api
Product: Red Hat 3scale API Management Platform 2Fixed in: 3amp-system
redhatend of lifevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: ruby
redhatend of lifevia redhat_api
Product: Red Hat Software CollectionsFixed in: rh-ruby24-ruby

Vendor Advisories (3)

microsoft2020-Sep/CVE-2019-16255

CVE-2019-16255

Sep 8, 2020
redhatCVE-2019-16255Moderate

ruby: Code injection via command argument of Shell#test / Shell#[]

Nov 26, 2019
microsoft2019-Nov/CVE-2019-16255Important

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.

Nov 12, 2019

References

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