CVE-2021-39921: Null Pointer Dereference
First published: Fri Nov 19 2021(Updated: )
NULL pointer exception in the Modbus 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
Credit: cve@gitlab.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| debian/wireshark | 2.6.20-0+deb10u4 2.6.20-0+deb10u7 3.4.10-0+deb11u1 4.0.6-1~deb12u1 4.0.10-1 | |
| Wireshark Wireshark | >=3.2.0<=3.2.17 | |
| Wireshark Wireshark | >=3.4.0<=3.4.9 | |
| Fedoraproject Fedora | =34 | |
| Fedoraproject Fedora | =35 | |
| Debian Debian Linux | =9.0 |
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Reference Links
- https://gitlab.com/wireshark/wireshark/-/issues/17703
- https://www.wireshark.org/security/wnpa-sec-2021-14.html
- https://security-tracker.debian.org/tracker/CVE-2021-39921
- https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39921.json
- https://lists.debian.org/debian-lts-announce/2021/12/msg00015.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/A6AJFIYIHS3TYDD2EBYBJ5KKE52X34BJ/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/YEWTIRMC2MFQBZ2O5M4CJHJM4JPBHLXH/
- https://security.gentoo.org/glsa/202210-04
- https://www.debian.org/security/2021/dsa-5019
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YEWTIRMC2MFQBZ2O5M4CJHJM4JPBHLXH/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A6AJFIYIHS3TYDD2EBYBJ5KKE52X34BJ/
Frequently Asked Questions
What is CVE-2021-39921?
CVE-2021-39921 is a vulnerability in the Modbus dissector in Wireshark that allows denial of service through packet injection or crafted capture file.
Which versions of Wireshark are affected by CVE-2021-39921?
Wireshark versions 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 are affected by CVE-2021-39921.
How can CVE-2021-39921 be exploited?
CVE-2021-39921 can be exploited by performing packet injection or using a crafted capture file in Wireshark.
What is the severity of CVE-2021-39921?
CVE-2021-39921 has a severity rating of high (7.5).
How do I fix CVE-2021-39921?
To fix CVE-2021-39921, update Wireshark to version 3.4.10 or higher.
- collector/security-tracker-debian
- collector/nvd-index
- agent/software-canonical-lookup
- collector/mitre-cve
- source/MITRE
- agent/remedy
- agent/weakness
- agent/severity
- agent/author
- agent/last-modified-date
- agent/references
- agent/softwarecombine
- agent/type
- agent/description
- agent/first-publish-date
- agent/event
- agent/tags
- package-manager/debian
- vendor/wireshark
- canonical/wireshark wireshark
- version/wireshark wireshark/3.2.0
- version/wireshark wireshark/3.2.17
- version/wireshark wireshark/3.4.0
- version/wireshark wireshark/3.4.9
- vendor/fedoraproject
- canonical/fedoraproject fedora
- version/fedoraproject fedora/34
- version/fedoraproject fedora/35
- vendor/debian
- canonical/debian debian linux
- version/debian debian linux/9.0