CVE-2021-4190Public exploitNetwork attack vector

Application crash via stalled Kafka field offset

Published Dec 30, 2021 · Updated Nov 3, 2025

Denial of service in Wireshark 3.6.0 allows attackers to crash the analyzer through a malformed Kafka packet or capture file. The Kafka tagged-fields parser accepts a huge count, then repeatedly reads the same offset when an invalid varint consumes zero bytes. Live injection requires access to monitored traffic, while the file vector requires the trace to be opened; processing exhausts CPU and memory before the application fails.

CVSS severity7.5
High
EPSS probability3.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Wireshark 3.6.0 allows attackers to crash the analyzer through a malformed Kafka packet or capture file. The Kafka tagged-fields parser accepts a huge count, then repeatedly reads the same offset when an invalid varint consumes zero bytes. Live injection requires access to monitored traffic, while the file vector requires the trace to be opened; processing exhausts CPU and memory before the application fails.

The record

CVE
CVE-2021-4190
Published
Dec 30, 2021
Updated
Nov 3, 2025
Vendor
Wireshark Foundation
Product
Wireshark
Classifications
CWE-834, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 30, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion==3.6.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Wireshark Foundation · Wiresharkversion==3.6.0

Published CVSS scores

7.5GitLab Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-834Excessive Iteration
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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