CVE-2021-4183Public exploit

Application crash via pcapng heap over-read

Published Dec 30, 2021 · Updated Aug 3, 2024

Heap-buffer overflow in Wireshark 3.6.0 allows attackers to crash the application by supplying a malformed pcapng capture file. The pcapng_process_options function reads a two-byte option value beyond its allocated heap buffer while TShark or Wireshark parses the crafted capture. Exploitation requires a user to open the file, and the demonstrated consequence is process termination rather than data access or modification.

CVSS severity5.5
Medium
EPSS probability1.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Heap-buffer overflow in Wireshark 3.6.0 allows attackers to crash the application by supplying a malformed pcapng capture file. The pcapng_process_options function reads a two-byte option value beyond its allocated heap buffer while TShark or Wireshark parses the crafted capture. Exploitation requires a user to open the file, and the demonstrated consequence is process termination rather than data access or modification.

The record

CVE
CVE-2021-4183
Published
Dec 30, 2021
Updated
Aug 3, 2024
Vendor
Wireshark Foundation
Product
Wireshark
Classifications
CWE-125, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 30, 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==3.6.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Wireshark Foundation · Wiresharkversion==3.6.0

Published CVSS scores

5.5GitLab Inc.CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
4.3NIST NVDAV:N/AC:M/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1204.002Malicious File

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo