CVE-2021-39928

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 5.9% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-11-18 · updated 2026-06-17
Weakness: CWE-476

Description

NULL pointer exception in the IEEE 802.11 dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

Affected products

Debian Linux: 9.0
Fedoraproject Fedora: 34, 35
Wireshark Foundation Wireshark: from 3.2.0 before 3.2.18; from 3.4.0 before 3.4.10 — fixed in 3.2.18, 3.4.10

How to fix

Upgrade to a fixed version: Wireshark Foundation Wireshark 3.2.18, 3.4.10. Check the vendor advisory for mitigations.

References

https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39928.json
https://gitlab.com/wireshark/wireshark/-/issues/17704
https://lists.debian.org/debian-lts-announce/2021/12/msg00015.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A6AJFIYIHS3TYDD2EBYBJ5KKE52X34BJ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YEWTIRMC2MFQBZ2O5M4CJHJM4JPBHLXH/
https://security.gentoo.org/glsa/202210-04
https://www.debian.org/security/2021/dsa-5019
https://www.wireshark.org/security/wnpa-sec-2021-13.html
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39928.json
https://gitlab.com/wireshark/wireshark/-/issues/17704
https://lists.debian.org/debian-lts-announce/2021/12/msg00015.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A6AJFIYIHS3TYDD2EBYBJ5KKE52X34BJ/

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