CVE-2016-4303

Exp

The parse_string function in cjson.c in the cJSON library mishandles UTF8/16 strings, which allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a non-hex character in a JSON string, which triggers a heap-based buffer overflow.

Published: 2016-09-26 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-4303 is rated High Exploit Risk (88.2/100): CVSS Critical severity, with high exploitation likelihood (EPSS 7.58%, 92th percentile). 2 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.85% 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-2016-4303

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

Exploit prediction scoring system (EPSS) score for CVE-2016-4303

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 2026-05-28 5.73% 7.58% +1.85%
2 2025-09-22 5.76% 5.73% -0.03%
3 2025-03-30 — 5.76% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-4303

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/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-2016-4303

OS Trackers for CVE-2016-4303

vendor priority summary link
debian not yet assigned CVE-2016-4303 not yet assigned priority: Debian including 1 source packages (iperf3), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2016-4303
suse critical CVE-2016-4303 severity critical: SUSE including 11 source package names (iperf, iperf-3.1.3-1.3, …), 13 product×package rows across 5 product lines (SUSE Enterprise Storage 4, SUSE Enterprise Storage 6, … (5 product lines)): Fixed 9, Known Not Affected 4. https://www.suse.com/security/cve/CVE-2016-4303/
ubuntu medium CVE-2016-4303 medium priority: Ubuntu including 2 source packages (iperf, iperf3), 34 status rows across 17 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, precise, trusty, upstream, wily, xenial, yakkety, zesty): not-affected 25, ignored 4, DNE 2, released 2, needs-triage 1. https://ubuntu.com/security/CVE-2016-4303

Affected software / configurations for CVE-2016-4303

Vendor Product Version Raw CPE
es iperf3 >= 3.0, < 3.0.12 cpe:2.3:a:es:iperf3:*:*:*:*:*:*:*:*
es iperf3 >= 3.1, < 3.1.3 cpe:2.3:a:es:iperf3:*:*:*:*:*:*:*:*
novell suse_package_hub_for_suse_linux_enterprise 12 cpe:2.3:a:novell:suse_package_hub_for_suse_linux_enterprise:12:*:*:*:*:*:*:*
opensuse leap 42.1 cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:*
opensuse opensuse 13.2 cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*

References for CVE-2016-4303

URL Tags
http://blog.talosintel.com/2016/06/esnet-vulnerability.html Exploit Third Party Advisory
http://lists.opensuse.org/opensuse-updates/2016-08/msg00082.html Mailing List Third Party Advisory
http://lists.opensuse.org/opensuse-updates/2016-08/msg00090.html Mailing List Third Party Advisory
http://software.es.net/iperf/news.html#security-issue-iperf-3-1-3-iperf-3-0-12-released Release Notes Third Party Advisory
http://www.talosintelligence.com/reports/TALOS-2016-0164/ Exploit Third Party Advisory
https://github.com/esnet/iperf/commit/91f2fa59e8ed80dfbf400add0164ee0e508e412a Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/01/msg00023.html Mailing List Third Party Advisory
https://raw.githubusercontent.com/esnet/security/master/cve-2016-4303/esnet-secadv-2016-0001.txt.asc Third Party Advisory
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