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Fencer Vulns
high 7.5

CVE-2021-4190 json

Large loop in the Kafka dissector in Wireshark 3.6.0 allows denial of service via packet injection or crafted capture file

published 2021-12-30 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34050

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
3.3%
EPSS 3.3% chance of exploitation in 30 days, percentile 88%
public exploits
0
none known

Summary

Large loop in the Kafka dissector in Wireshark 3.6.0 allows denial of service via packet injection or crafted capture file

Patch / fix

  • wireshark wireshark 3.4.12
  • wireshark Debian 14, Debian 13, Debian 12 3.6.2-1

debian advisories DEBIAN-CVE-2021-4190

  • wireshark SLES for SAP 15 SP2, SLES for SAP 15 SP1, SLES for SAP 15 +18 more 3.6.1-3.68.1
  • libvirt SLE Module for Server Applications 15 SP3, SLE Module for Basesystem 15 SP3, SLE Micro 5.1 7.1.0-150300.6.23.1

suse advisories SUSE-SU-2022:0375-1

  • wireshark openSUSE Tumbleweed 3.6.1-2.1
  • wireshark openSUSE Leap 15.3 3.6.1-3.68.1
  • libvirt openSUSE Leap 15.3 7.1.0-150300.6.23.1

opensuse advisories openSUSE-SU-2024:11707-1openSUSE-SU-2022:0375-1

  • wireshark CBL-Mariner 2.0 3.4.14-1

azure linux advisories AZL-9100

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2021-4190 updated cvss 7.5

wireshark: Kafka dissector infinite loop

  • Red Hat Enterprise Linux 9 wireshark, wireshark-cli
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 6 wireshark, wireshark-gnome Red Hat Enterprise Linux 7 wireshark, wireshark-gnome Red Hat Enterprise Linux 8 wireshark, wireshark-cli
    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

3.33% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • gitlab.com https://gitlab.com/wireshark/wireshark/-/issues/17811 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • Wireshark Foundation Wireshark

Classification

Weakness

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.