CVE-2021-22235Public exploitNetwork attack vector

Denial of service via mismatched buffer deallocation

Published Jul 20, 2021 · Updated Aug 3, 2024

Invalid memory deallocation in Wireshark 3.2.0 through 3.2.14 and 3.4.0 through 3.4.6 allows attackers to crash it via DNP data. On the CRC-error path, dissect_dnp3_message calls g_free on al_buffer even though the buffer belongs to the packet-scope wmem pool. A malformed DNP packet injected into a live capture or opened from a crafted capture file terminates Wireshark or TShark.

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

What happened

Invalid memory deallocation in Wireshark 3.2.0 through 3.2.14 and 3.4.0 through 3.4.6 allows attackers to crash it via DNP data. On the CRC-error path, dissect_dnp3_message calls g_free on al_buffer even though the buffer belongs to the packet-scope wmem pool. A malformed DNP packet injected into a live capture or opened from a crafted capture file terminates Wireshark or TShark.

The record

CVE
CVE-2021-22235
Published
Jul 20, 2021
Updated
Aug 3, 2024
Vendor
Wireshark Foundation
Product
Wireshark
Classifications
CWE-835, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record 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=>=3.2.0, <3.2.15
  2. Affected versionversion=>=3.4.0, <3.4.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Wireshark Foundation · Wiresharkversion=>=3.2.0, <3.2.15; version=>=3.4.0, <3.4.7

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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 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')
T1499.004Application 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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