CVE-2021-39923
HIGHCVSS 7.5/10EPSS 1.52%
Last modified
CVE-2021-39923 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Large loop in the PNRP 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. EPSS estimates a 1.52% chance of exploitation in the next 30 days.
Description
Large loop in the PNRP 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
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Wireshark | Wireshark | >= 3.2.0, <= 3.2.17 |
| Wireshark | Wireshark | >= 3.4.0, <= 3.4.9 |
| Debian | Debian Linux | 10.0 |
| Debian | Debian Linux | 11.0 |
| Debian | Debian Linux | 9.0 |
References
- https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39923.jsonThird Party Advisory
- https://gitlab.com/wireshark/wireshark/-/issues/17684Issue Tracking, Patch, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2021/12/msg00015.htmlMailing List, Third Party Advisory
- https://www.debian.org/security/2021/dsa-5019Third Party Advisory
- https://www.wireshark.org/security/wnpa-sec-2021-11.htmlVendor Advisory
- https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39923.jsonThird Party Advisory
- https://gitlab.com/wireshark/wireshark/-/issues/17684Issue Tracking, Patch, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2021/12/msg00015.htmlMailing List, Third Party Advisory
- https://www.debian.org/security/2021/dsa-5019Third Party Advisory
- https://www.wireshark.org/security/wnpa-sec-2021-11.htmlVendor Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2021-39923?
Large loop in the PNRP 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
How severe is CVE-2021-39923?
CVE-2021-39923 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.52% probability of exploitation in the next 30 days.
How do I fix CVE-2021-39923?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
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Are you affected by CVE-2021-39923?
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Scan your code nowSource: NVD / NIST