CVE-2021-4181Network attack vector

Application crash via excess Sysdig event parameters

Published Dec 30, 2021 · Updated Nov 3, 2025

Out-of-bounds read in Wireshark 3.6.0 and 3.4.0 through 3.4.10 allows attackers to crash the application via malformed input. The Sysdig Event dissector indexes parameter metadata beyond the known event definition when an event supplies more parameters than Wireshark expects. A malformed packet injected onto a monitored network reaches the flaw without authentication; opening a crafted capture file requires user interaction.

CVSS severity7.5
High
EPSS probability3.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Wireshark 3.6.0 and 3.4.0 through 3.4.10 allows attackers to crash the application via malformed input. The Sysdig Event dissector indexes parameter metadata beyond the known event definition when an event supplies more parameters than Wireshark expects. A malformed packet injected onto a monitored network reaches the flaw without authentication; opening a crafted capture file requires user interaction.

The record

CVE
CVE-2021-4181
Published
Dec 30, 2021
Updated
Nov 3, 2025
Vendor
Wireshark Foundation
Product
Wireshark
Classifications
CWE-125, T1204.002, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=>=3.4.0, <3.4.10
  2. Affected versionversion==3.6.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Wireshark Foundation · Wiresharkversion=>=3.4.0, <3.4.10; version==3.6.0

Published CVSS scores

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

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1204.002Malicious File
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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