Improper input validation in Cisco Adaptive Security Appliance Software
Priority MEDIUM 47CWE-20Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01857 79th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Cisco | Cisco Adaptive Security Appliance (ASA) Software | all versions | — | No fix listed | CNA |
- Cisco Adaptive Security Appliance (ASA) Software VendorCisco Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 38
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:* | 6.2.3 to before 6.2.3.16; 6.3.0 to before 6.3.0.6; 6.4.0 to before 6.4.0.6 | Vulnerable | Cisco |
| cpe:2.3:o:cisco:asa_5505_firmware:9.4\(1\):*:*:*:*:*:*:* | 9.4(1) | Vulnerable | Cisco |
| cpe:2.3:o:cisco:asa_5505_firmware:96.4\(0.42\):*:*:*:*:*:*:* | 96.4(0.42) | Vulnerable | Cisco |
| cpe:2.3:h:cisco:asa_5505:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:o:cisco:asa_5510_firmware:9.4\(1\):*:*:*:*:*:*:* | 9.4(1) | Vulnerable | Cisco |
| cpe:2.3:o:cisco:asa_5510_firmware:96.4\(0.42\):*:*:*:*:*:*:* | 96.4(0.42) | Vulnerable | Cisco |
| cpe:2.3:h:cisco:asa_5510:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:o:cisco:asa_5512-x_firmware:9.4\(1\):*:*:*:*:*:*:* | 9.4(1) | Vulnerable | Cisco |
| cpe:2.3:o:cisco:asa_5512-x_firmware:96.4\(0.42\):*:*:*:*:*:*:* | 96.4(0.42) | Vulnerable | Cisco |
| cpe:2.3:h:cisco:asa_5512-x:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
- cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:* Versions 6.2.3 to before 6.2.3.16; 6.3.0 to before 6.3.0.6; 6.4.0 to before 6.4.0.6 Vulnerable ·Cisco
- cpe:2.3:o:cisco:asa_5505_firmware:9.4\(1\):*:*:*:*:*:*:* Versions 9.4(1) Vulnerable ·Cisco
- cpe:2.3:o:cisco:asa_5505_firmware:96.4\(0.42\):*:*:*:*:*:*:* Versions 96.4(0.42) Vulnerable ·Cisco
- cpe:2.3:h:cisco:asa_5505:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:o:cisco:asa_5510_firmware:9.4\(1\):*:*:*:*:*:*:* Versions 9.4(1) Vulnerable ·Cisco
- cpe:2.3:o:cisco:asa_5510_firmware:96.4\(0.42\):*:*:*:*:*:*:* Versions 96.4(0.42) Vulnerable ·Cisco
- cpe:2.3:h:cisco:asa_5510:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:o:cisco:asa_5512-x_firmware:9.4\(1\):*:*:*:*:*:*:* Versions 9.4(1) Vulnerable ·Cisco
- cpe:2.3:o:cisco:asa_5512-x_firmware:96.4\(0.42\):*:*:*:*:*:*:* Versions 96.4(0.42) Vulnerable ·Cisco
- cpe:2.3:h:cisco:asa_5512-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
Show 28 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:cisco:asa_5515-x_firmware:9.4\(1\):*:*:*:*:*:*:* | 9.4(1) | Vulnerable | Cisco |
| cpe:2.3:o:cisco:asa_5515-x_firmware:96.4\(0.42\):*:*:*:*:*:*:* | 96.4(0.42) | Vulnerable | Cisco |
| cpe:2.3:h:cisco:asa_5515-x:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:o:cisco:asa_5520_firmware:9.4\(1\):*:*:*:*:*:*:* | 9.4(1) | Vulnerable | Cisco |
| cpe:2.3:o:cisco:asa_5520_firmware:96.4\(0.42\):*:*:*:*:*:*:* | 96.4(0.42) | Vulnerable | Cisco |
| cpe:2.3:h:cisco:asa_5520:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:o:cisco:asa_5525-x_firmware:9.4\(1\):*:*:*:*:*:*:* | 9.4(1) | Vulnerable | Cisco |
| cpe:2.3:o:cisco:asa_5525-x_firmware:96.4\(0.42\):*:*:*:*:*:*:* | 96.4(0.42) | Vulnerable | Cisco |
| cpe:2.3:h:cisco:asa_5525-x:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:o:cisco:asa_5540_firmware:9.4\(1\):*:*:*:*:*:*:* | 9.4(1) | Vulnerable | Cisco |
| cpe:2.3:o:cisco:asa_5540_firmware:96.4\(0.42\):*:*:*:*:*:*:* | 96.4(0.42) | Vulnerable | Cisco |
| cpe:2.3:h:cisco:asa_5540:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:o:cisco:asa_5545-x_firmware:9.4\(1\):*:*:*:*:*:*:* | 9.4(1) | Vulnerable | Cisco |
| cpe:2.3:o:cisco:asa_5545-x_firmware:96.4\(0.42\):*:*:*:*:*:*:* | 96.4(0.42) | Vulnerable | Cisco |
| cpe:2.3:h:cisco:asa_5545-x:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:o:cisco:asa_5550_firmware:9.4\(1\):*:*:*:*:*:*:* | 9.4(1) | Vulnerable | Cisco |
| cpe:2.3:o:cisco:asa_5550_firmware:96.4\(0.42\):*:*:*:*:*:*:* | 96.4(0.42) | Vulnerable | Cisco |
| cpe:2.3:h:cisco:asa_5550:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:o:cisco:asa_5555-x_firmware:9.4\(1\):*:*:*:*:*:*:* | 9.4(1) | Vulnerable | Cisco |
| cpe:2.3:o:cisco:asa_5555-x_firmware:96.4\(0.42\):*:*:*:*:*:*:* | 96.4(0.42) | Vulnerable | Cisco |
| cpe:2.3:h:cisco:asa_5555-x:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:o:cisco:asa_5580_firmware:9.4\(1\):*:*:*:*:*:*:* | 9.4(1) | Vulnerable | Cisco |
| cpe:2.3:o:cisco:asa_5580_firmware:96.4\(0.42\):*:*:*:*:*:*:* | 96.4(0.42) | Vulnerable | Cisco |
| cpe:2.3:h:cisco:asa_5580:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:o:cisco:asa_5585-x_firmware:9.4\(1\):*:*:*:*:*:*:* | 9.4(1) | Vulnerable | Cisco |
| cpe:2.3:o:cisco:asa_5585-x_firmware:96.4\(0.42\):*:*:*:*:*:*:* | 96.4(0.42) | Vulnerable | Cisco |
| cpe:2.3:h:cisco:asa_5585-x:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:* | 9.6 to before 9.6.4.36; 9.8 to before 9.8.4.12; 9.9 to before 9.9.2.66; 9.10 to before 9.10.1.37; 9.12 to before 9.12.2.9 | Vulnerable | Cisco |
- cpe:2.3:o:cisco:asa_5515-x_firmware:9.4\(1\):*:*:*:*:*:*:* Versions 9.4(1) Vulnerable ·Cisco
- cpe:2.3:o:cisco:asa_5515-x_firmware:96.4\(0.42\):*:*:*:*:*:*:* Versions 96.4(0.42) Vulnerable ·Cisco
- cpe:2.3:h:cisco:asa_5515-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:o:cisco:asa_5520_firmware:9.4\(1\):*:*:*:*:*:*:* Versions 9.4(1) Vulnerable ·Cisco
- cpe:2.3:o:cisco:asa_5520_firmware:96.4\(0.42\):*:*:*:*:*:*:* Versions 96.4(0.42) Vulnerable ·Cisco
- cpe:2.3:h:cisco:asa_5520:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:o:cisco:asa_5525-x_firmware:9.4\(1\):*:*:*:*:*:*:* Versions 9.4(1) Vulnerable ·Cisco
- cpe:2.3:o:cisco:asa_5525-x_firmware:96.4\(0.42\):*:*:*:*:*:*:* Versions 96.4(0.42) Vulnerable ·Cisco
- cpe:2.3:h:cisco:asa_5525-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:o:cisco:asa_5540_firmware:9.4\(1\):*:*:*:*:*:*:* Versions 9.4(1) Vulnerable ·Cisco
- cpe:2.3:o:cisco:asa_5540_firmware:96.4\(0.42\):*:*:*:*:*:*:* Versions 96.4(0.42) Vulnerable ·Cisco
- cpe:2.3:h:cisco:asa_5540:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:o:cisco:asa_5545-x_firmware:9.4\(1\):*:*:*:*:*:*:* Versions 9.4(1) Vulnerable ·Cisco
- cpe:2.3:o:cisco:asa_5545-x_firmware:96.4\(0.42\):*:*:*:*:*:*:* Versions 96.4(0.42) Vulnerable ·Cisco
- cpe:2.3:h:cisco:asa_5545-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:o:cisco:asa_5550_firmware:9.4\(1\):*:*:*:*:*:*:* Versions 9.4(1) Vulnerable ·Cisco
- cpe:2.3:o:cisco:asa_5550_firmware:96.4\(0.42\):*:*:*:*:*:*:* Versions 96.4(0.42) Vulnerable ·Cisco
- cpe:2.3:h:cisco:asa_5550:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:o:cisco:asa_5555-x_firmware:9.4\(1\):*:*:*:*:*:*:* Versions 9.4(1) Vulnerable ·Cisco
- cpe:2.3:o:cisco:asa_5555-x_firmware:96.4\(0.42\):*:*:*:*:*:*:* Versions 96.4(0.42) Vulnerable ·Cisco
- cpe:2.3:h:cisco:asa_5555-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:o:cisco:asa_5580_firmware:9.4\(1\):*:*:*:*:*:*:* Versions 9.4(1) Vulnerable ·Cisco
- cpe:2.3:o:cisco:asa_5580_firmware:96.4\(0.42\):*:*:*:*:*:*:* Versions 96.4(0.42) Vulnerable ·Cisco
- cpe:2.3:h:cisco:asa_5580:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:o:cisco:asa_5585-x_firmware:9.4\(1\):*:*:*:*:*:*:* Versions 9.4(1) Vulnerable ·Cisco
- cpe:2.3:o:cisco:asa_5585-x_firmware:96.4\(0.42\):*:*:*:*:*:*:* Versions 96.4(0.42) Vulnerable ·Cisco
- cpe:2.3:h:cisco:asa_5585-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:* Versions 9.6 to before 9.6.4.36; 9.8 to before 9.8.4.12; 9.9 to before 9.9.2.66; 9.10 to before 9.10.1.37; 9.12 to before 9.12.2.9 Vulnerable ·Cisco
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2020-3191
- 2026-10-03 Alias added: GHSA-54hx-xv6r-c55r
References
More Cisco Adaptive Security Appliance Software vulnerabilities
- TI-2025-14628 Buffer overflow in Cisco Secure Firewall Adaptive Security Appliance Software KEVCVSS 3.1CRITICAL 9.9
- TI-2016-05454 Buffer overflow in Cisco Adaptive Security Appliance (ASA) Software through 9.4.2.3 on… KEVCVSS 3.1HIGH 8.8
- TI-2023-06973 Authentication bypass in Cisco Adaptive Security Appliance Software KEVCVSS 3.1CRITICAL 9.1
- TI-2026-82192 Denial of service in Cisco Secure Firewall ASA and FTD SSL VPN KEVCVSS 3.1HIGH 8.6
- TI-2026-16533 Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense… KEVCVSS 3.1HIGH 8.6
- TI-2025-14657 Missing authorization in Cisco Secure Firewall Adaptive Security Appliance Software KEVCVSS 3.1HIGH 8.6
Sources
- CVE-2020-3191 · CVE Program
- CVE-2020-3191 · NVD
- FIRST EPSS
- GHSA-54hx-xv6r-c55r · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences