CVE-2021-4182Public exploitNetwork attack vector

Application hang via malformed RFC 7468 file

Published Dec 30, 2021 · Updated Nov 3, 2025

Infinite loop in Wireshark 3.6.0 and 3.4.0 through 3.4.10 allows attackers to cause an application hang via a malformed trace file. The RFC 7468 file parser repeatedly processes incomplete armored input instead of rejecting it as malformed, leaving its parsing loop unable to terminate. Exploitation requires the malformed trace to be opened or attacker-injected traffic to be processed, causing excessive CPU consumption and a sustained application hang.

CVSS severity7.5
High
EPSS probability3.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Infinite loop in Wireshark 3.6.0 and 3.4.0 through 3.4.10 allows attackers to cause an application hang via a malformed trace file. The RFC 7468 file parser repeatedly processes incomplete armored input instead of rejecting it as malformed, leaving its parsing loop unable to terminate. Exploitation requires the malformed trace to be opened or attacker-injected traffic to be processed, causing excessive CPU consumption and a sustained application hang.

The record

CVE
CVE-2021-4182
Published
Dec 30, 2021
Updated
Nov 3, 2025
Vendor
Wireshark Foundation
Product
Wireshark
Classifications
CWE-835, 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=>=3.4.0, <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

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-835Loop with Unreachable Exit Condition ('Infinite Loop')
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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