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Fencer Vulns
critical 9.8

CVE-2016-2339 json

An exploitable heap overflow vulnerability exists in the Fiddle::Function.new "initialize" function functionality of Ruby.

published 2017-01-06 9 y ago modified 2026-06-17 4 mo ago also EUVD-2016-3423

cvss
9.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.1%
EPSS 5.1% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

An exploitable heap overflow vulnerability exists in the Fiddle::Function.new "initialize" function functionality of Ruby. In Fiddle::Function.new "initialize" heap buffer "arg_types" allocation is made based on args array length. Specially constructed object passed as element of args array can increase this array size after mentioned allocation and cause heap overflow.

Patch / fix

  • ruby2.0 Ubuntu 14.04 LTS 2.0.0.484-1ubuntu2.4
  • ruby1.9.1 Ubuntu 14.04 LTS 1.9.3.484-2ubuntu1.3

ubuntu advisories UBUNTU-CVE-2016-2339

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • ruby2.1 SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +14 more 2.1.9-19.3.2
  • yast2-ruby-bindings SLES for SAP 12 SP2, SLES 12 SP2-LTSS, SLES 12 SP2-BCL +1 more 3.1.53-9.8.1
  • ruby2.1 SLES for SAP 12 SP2, SLES for SAP 12 SP1, SLES for Raspberry Pi 12 SP2 +6 more 2.1.9-15.1
  • ruby19 Studio Onsite Runner 1.3, Studio Onsite 1.3 1.9.3.p392-0.26.1

suse advisories SUSE-SU-2020:1570-1SUSE-SU-2017:1067-1SUSE-SU-2017:0914-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2016-2339 updated cvss 7.0

ruby: Fiddle:: Function.new heap buffer overflow

  • Red Hat CloudForms Management Engine 5 ruby-200-ruby, rh-ruby22-ruby Red Hat Enterprise Linux 7 ruby, ruby-irb, rubygems, ruby-libs, ruby-tcltk, rubygem-json, +6 more Red Hat Software Collections ruby200-ruby, rh-ruby22-ruby, rh-ruby23-ruby, ruby200-ruby-irb, ruby200-rubygems, ruby200-ruby-libs, +36 more
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 5 ruby Red Hat Enterprise Linux 6 ruby, ruby-ri, ruby-irb, ruby-libs, ruby-rdoc, ruby-tcltk
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

5.14% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • talosintelligence.com http://www.talosintelligence.com/reports/TALOS-2016-0034/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • Ruby Ruby

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.