CVE-2016-2339

Exp

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.

Published: 2017-01-06 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-2339 is rated High Exploit Risk (90.5/100): CVSS Critical severity, with high exploitation likelihood (EPSS 5.14%, 91th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +4.31% 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-2016-2339

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

Exploit prediction scoring system (EPSS) score for CVE-2016-2339

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 0.83% 5.14% +4.31%
2 2026-05-27 0.89% 0.83% -0.06%
3 2026-05-21 — 0.89% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-2339

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
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.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/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:L)
Exploitation conditions are straightforward and predictable.
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.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2016-2339

OS Trackers for CVE-2016-2339

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2016-2339
suse medium CVE-2016-2339 severity moderate: SUSE including 26 source package names (4.0.0:libruby2_1-2_1-2.1.9-15.1, 4.0.0:ruby2.1-2.1.9-15.1, …), 193 product×package rows across 67 product lines (Container caasp/v4/velum, HPE Helion OpenStack 8, … (67 product lines)): Fixed 167, Known Not Affected 26. https://www.suse.com/security/cve/CVE-2016-2339/
ubuntu low CVE-2016-2339 low priority: Ubuntu including 4 source packages (ruby1.8, ruby1.9.1, ruby2.0, ruby2.3), 24 status rows across 6 suites (precise, trusty, upstream, xenial, yakkety, zesty): DNE 13, needs-triage 4, not-affected 3, ignored 2, released 2. https://ubuntu.com/security/CVE-2016-2339

Affected software / configurations for CVE-2016-2339

Vendor Product Version Raw CPE
ruby-lang ruby 2.2.2 cpe:2.3:a:ruby-lang:ruby:2.2.2:*:*:*:*:*:*:*
ruby-lang ruby 2.3.0 cpe:2.3:a:ruby-lang:ruby:2.3.0:*:*:*:*:*:*:*

References for CVE-2016-2339

cvelogic Threat Intelligence