CVE-2019-16255

Exp

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.

Published: 2019-11-26 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-16255 is rated High Exploit Risk (81.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 4.20%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +3.04% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2019-16255

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2019-16255

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.16% 4.20% +3.04%
2 2026-03-21 1.38% 1.16% -0.23%
3 2026-02-18 — 1.38% —

Full EPSS history (27 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-16255

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2019-16255

OS Trackers for CVE-2019-16255

vendor priority summary link
alpine high CVE-2019-16255: 1 source package rows (ruby); 30 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 20. https://security.alpinelinux.org/vuln/CVE-2019-16255
debian not yet assigned CVE-2019-16255 not yet assigned priority: Debian including 1 source packages (jruby), 4 status rows across 4 suites (bookworm, forky, sid, trixie): resolved 4. https://security-tracker.debian.org/tracker/CVE-2019-16255
gentoo normal CVE-2019-16255: 1 GLSA(s) (202003-06), 1 atom(s) (dev-lang/ruby); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2019-16255
redhat medium — https://access.redhat.com/security/cve/CVE-2019-16255
suse medium CVE-2019-16255 severity moderate: SUSE including 311 source package names (2.17-17.3:libruby2_5-2_5-2.5.7-4.8.1, 2.17-17.3:ruby2.5-2.5.7-4.8.1, …), 1032 product×package rows across 253 product lines (Container bci/ruby, Container suse/rmt-server, … (253 product lines)): Fixed 860, Known Affected 157, Known Not Affected 9, Will Not Fix 6. https://www.suse.com/security/cve/CVE-2019-16255/
ubuntu medium CVE-2019-16255 medium priority: Ubuntu including 3 source packages (jruby, ruby2.3, ruby2.5), 52 status rows across 18 suites (bionic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 30, ignored 9, needs-triage 7, released 6. https://ubuntu.com/security/CVE-2019-16255

Affected software / configurations for CVE-2019-16255

Vendor Product Version Raw CPE
ruby-lang ruby >= 2.4.0, <= 2.4.7 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
ruby-lang ruby >= 2.5.0, <= 2.5.6 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
ruby-lang ruby >= 2.6.0, <= 2.6.4 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
oracle graalvm 19.3.0.2 cpe:2.3:a:oracle:graalvm:19.3.0.2:*:*:*:enterprise:*:*:*

References for CVE-2019-16255

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00041.html Third Party Advisory
https://hackerone.com/reports/327512 Exploit Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/11/msg00025.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/12/msg00009.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/08/msg00027.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html
https://seclists.org/bugtraq/2019/Dec/31 Broken Link Mailing List Third Party Advisory
https://seclists.org/bugtraq/2019/Dec/32 Broken Link Mailing List Third Party Advisory
https://security.gentoo.org/glsa/202003-06 Third Party Advisory
https://www.debian.org/security/2019/dsa-4587 Third Party Advisory
https://www.oracle.com/security-alerts/cpujan2020.html Patch 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
cvelogic Threat Intelligence