What is CVE-2021-4184?

CVE-2021-4184 is a high-severity vulnerability in Oracle HTTP Server, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 7.5/10. Published 2021-12-30.

How severe is CVE-2021-4184?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2021-4184 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Oracle HTTP Server

CVE-2021-4184

Infinite loop in the BitTorrent DHT dissector in Wireshark 3.6.0 and 3.4.0 to 3.4.10 allows denial of service via packet injection or crafted capture file

Published 2021-12-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.038 (89.6th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 90th percentile — 89.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.039 · newest: 0.038 · change: -0.001

Affected products

Oracle HTTP Server — versions 12.2.1.3.0, 12.2.1.4.0
Oracle Zfs Storage Appliance Kit — versions 8.8
Wireshark — versions 3.6.0
Wireshark Foundation — versions =3.6.0, >=3.4.0, <3.4.10
Debian Linux — versions 9.0
Fedoraproject Fedora — versions 34, 35

Weakness classification (CWE)

CWE-835 — Loop with Unreachable Exit Condition (Infinite Loop)

Public proof-of-concept exploits

ARPSyndicate/cve-scores

References

www.wireshark.org/security/wnpa-sec-2021-18.html (Vendor Advisory)
gitlab.com/wireshark/wireshark/-/issues/17754 (Exploit, Third Party Advisory, Issue Tracking)
gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-4184.json (Third Party Advisory)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
lists.debian.org/debian-lts-announce/2022/03/msg00041.html (mailing-list, Mailing List, Third Party Advisory)
www.oracle.com/security-alerts/cpuapr2022.html (Third Party Advisory)
security.gentoo.org/glsa/202210-04 (vendor-advisory, Third Party Advisory)
af854a3a-2127-422b-91ae-364da2661108

Frequently asked questions

What is CVE-2021-4184?: CVE-2021-4184 is a high-severity vulnerability in Oracle HTTP Server, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 7.5/10. Published 2021-12-30.
How severe is CVE-2021-4184?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2021-4184 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.