CVE-2021-22173Public exploitNetwork attack vector

Denial of service via USB HID memory leak

Published Feb 17, 2021 · Updated Aug 3, 2024

A memory leak in the USB HID dissector in Wireshark 3.4.0 through 3.4.2 allows attackers to exhaust resources via malformed input. The USB HID decoding path uses mismatched g_strdup() and g_free() allocation handling; the fix moves formatted strings into packet-scoped memory. Reachability requires injection of a malformed packet onto a monitored network or interaction that causes a crafted capture file to be opened, resulting in excessive resource consumption.

CVSS severity7.5
High
EPSS probability2.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A memory leak in the USB HID dissector in Wireshark 3.4.0 through 3.4.2 allows attackers to exhaust resources via malformed input. The USB HID decoding path uses mismatched g_strdup() and g_free() allocation handling; the fix moves formatted strings into packet-scoped memory. Reachability requires injection of a malformed packet onto a monitored network or interaction that causes a crafted capture file to be opened, resulting in excessive resource consumption.

The record

CVE
CVE-2021-22173
Published
Feb 17, 2021
Updated
Aug 3, 2024
Vendor
Wireshark Foundation
Product
Wireshark
Classifications
CWE-401, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 17, 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

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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, <3.4.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Wireshark Foundation · Wiresharkversion=>=3.4.0, <3.4.3

Published CVSS scores

7.5NIST NVDCVSS: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
3.7GitLab Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

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-401Missing Release of Memory after Effective Lifetime
T1499Endpoint Denial of Service

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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