CVE-2018-16396

An issue was discovered in Ruby before 2.3.8, 2.4.x before 2.4.5, 2.5.x before 2.5.2, and 2.6.x before 2.6.0-preview3. It does not taint strings that result from unpacking tainted strings with some formats.

Published: 2018-11-16 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-16396 is rated High Risk (70.1/100): CVSS High severity, with high exploitation likelihood (EPSS 7.97%, 94th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +4.84% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

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

Exploit prediction scoring system (EPSS) score for CVE-2018-16396

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 3.13% 7.97% +4.84%
2 2026-06-02 3.29% 3.13% -0.16%
3 2026-03-04 — 3.29% —

Full EPSS history (63 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-16396

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.0 HIGH
CVSS:3.0/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-2018-16396

OS Trackers for CVE-2018-16396

vendor priority summary link
alpine high CVE-2018-16396: 1 source package rows (ruby); 24 state rows across 9 repos (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 9, open 15. https://security.alpinelinux.org/vuln/CVE-2018-16396
redhat medium — https://access.redhat.com/security/cve/CVE-2018-16396
suse medium CVE-2018-16396 severity moderate: SUSE including 309 source package names (2.17-17.3:libruby2_5-2_5-2.5.5-4.3.1, 2.17-17.3:ruby2.5-2.5.5-4.3.1, …), 1022 product×package rows across 252 product lines (Container bci/ruby, Container suse/rmt-server, … (252 product lines)): Fixed 842, Known Affected 157, Known Not Affected 23. https://www.suse.com/security/cve/CVE-2018-16396/
ubuntu medium CVE-2018-16396 medium priority: Ubuntu including 4 source packages (ruby1.9.1, ruby2.0, ruby2.3, ruby2.5), 20 status rows across 5 suites (bionic, cosmic, trusty, upstream, xenial): DNE 11, released 5, needs-triage 4. https://ubuntu.com/security/CVE-2018-16396

Affected software / configurations for CVE-2018-16396

Vendor Product Version Raw CPE
ruby-lang ruby >= 2.3.0, <= 2.3.7 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
ruby-lang ruby >= 2.4.0, <= 2.4.4 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
ruby-lang ruby >= 2.5.0, <= 2.5.1 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
ruby-lang ruby 2.6.0 cpe:2.3:a:ruby-lang:ruby:2.6.0:preview1:*:*:*:*:*:*
ruby-lang ruby 2.6.0 cpe:2.3:a:ruby-lang:ruby:2.6.0:preview2:*:*:*:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.10 cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
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:*:*:*:*:*:*:*
redhat enterprise_linux 6.0 cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
redhat enterprise_linux 7.4 cpe:2.3:o:redhat:enterprise_linux:7.4:*:*:*:*:*:*:*
redhat enterprise_linux 7.5 cpe:2.3:o:redhat:enterprise_linux:7.5:*:*:*:*:*:*:*
redhat enterprise_linux 7.6 cpe:2.3:o:redhat:enterprise_linux:7.6:*:*:*:*:*:*:*

References for CVE-2018-16396

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00036.html
http://www.securitytracker.com/id/1042106 Third Party Advisory VDB Entry
https://access.redhat.com/errata/RHSA-2018:3729 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:3730 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:3731 Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:2028
https://hackerone.com/reports/385070 Permissions Required Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/10/msg00020.html Third Party Advisory
https://security.netapp.com/advisory/ntap-20190221-0002/ Third Party Advisory
https://usn.ubuntu.com/3808-1/ Third Party Advisory
https://www.debian.org/security/2018/dsa-4332 Third Party Advisory
https://www.ruby-lang.org/en/news/2018/10/17/not-propagated-taint-flag-in-some-formats-of-pack-cve-2018-16396/ Vendor Advisory
https://www.ruby-lang.org/en/news/2018/10/17/ruby-2-3-8-released/ Release Notes
https://www.ruby-lang.org/en/news/2018/10/17/ruby-2-4-5-released/ Release Notes
https://www.ruby-lang.org/en/news/2018/10/17/ruby-2-5-2-released/ Release Notes
https://www.ruby-lang.org/en/news/2018/11/06/ruby-2-6-0-preview3-released/ Release Notes
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