CVE-2020-3191
No exploitation reported by the sources we read.
- Published2020-05-06
- Fixed in9.12.2.9 · 9.10.1.37 · 9.9.2.66 · 9.8.4.12 · 9.6.4.36
- WeaknessCWE-20
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
A vulnerability in DNS over IPv6 packet processing for Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to unexpectedly reload, resulting in a denial of service (DoS) condition. The vulnerability is due to improper length validation of a field in an IPv6 DNS packet. An attacker could exploit this vulnerability by sending a crafted DNS query over IPv6, which traverses the affected device. An exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. This vulnerability is specific to DNS over IPv6 traffic only.
Timeline
dates in UTC- 2020-05-0617:15CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-3191?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-3191?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 9.12 | ≥ 9.12, < 9.12.2.9 | 9.12.2.9 | NVD |
| 9.10 | ≥ 9.10, < 9.10.1.37 | 9.10.1.37 | NVD |
| 9.9 | ≥ 9.9, < 9.9.2.66 | 9.9.2.66 | NVD |
| 9.8 | ≥ 9.8, < 9.8.4.12 | 9.8.4.12 | NVD |
| 9.6 | ≥ 9.6, < 9.6.4.36 | 9.6.4.36 | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 6.4 | ≥ 6.4.0, < 6.4.0.6 | 6.4.0.6 | NVD |
| 6.3 | ≥ 6.3.0, < 6.3.0.6 | 6.3.0.6 | NVD |
| 6.2 | ≥ 6.2.3, < 6.2.3.16 | 6.2.3.16 | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 9.4 | = 9.4\(1\) | no fix published | NVD |
| 96.4 | = 96.4\(0.42\) | no fix published | NVD |
11 more products in the sources.
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
- Update Cisco ASA to 9.12.2.9 · 9.10.1.37 · 9.9.2.66 · 9.8.4.12 · 9.6.4.36
Advisories and patches
- tools.cisco.comVendor Advisory
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- Published
- 2020-05-06
- Last Modified
- 2026-08-11
- NVD status
- Modified
Frequently asked questions
What is CVE-2020-3191?
Is CVE-2020-3191 actively exploited?
What is the CVSS score for CVE-2020-3191?
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.