Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software IP Fragment Memory Leak Vulnerability
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-400.
Summary
A vulnerability in the IP fragment-handling implementation of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a memory leak on an affected device. This memory leak could prevent traffic from being processed through the device, resulting in a denial of service (DoS) condition. The vulnerability is due to improper error handling when specific failures occur during IP fragment reassembly. An attacker could exploit this vulnerability by sending crafted, fragmented IP traffic to a targeted device. A successful exploit could allow the attacker to continuously consume memory on the affected device and eventually impact traffic, resulting in a DoS condition. The device could require a manual reboot to recover from the DoS condition. Note: This vulnerability applies to both IP Version 4 (IPv4) and IP Version 6 (IPv6) traffic.
Why it matters now
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 · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:cisco:secure_firewall_threat_defense:6.6.0.1:*:*:*:*:*:*:* | 6.6.0.1 | Vulnerable | Cisco |
| cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.4.22:*:*:*:*:*:*:* | 9.8.4.22 | Vulnerable | Cisco |
| cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.4.25:*:*:*:*:*:*:* | 9.8.4.25 | Vulnerable | Cisco |
| cpe:2.3:o:cisco:adaptive_security_appliance_software:9.12.4.2:*:*:*:*:*:*:* | 9.12.4.2 | Vulnerable | Cisco |
| cpe:2.3:o:cisco:adaptive_security_appliance_software:9.12.4.3:*:*:*:*:*:*:* | 9.12.4.3 | Vulnerable | Cisco |
| cpe:2.3:o:cisco:adaptive_security_appliance_software:9.13.1.12:*:*:*:*:*:*:* | 9.13.1.12 | Vulnerable | Cisco |
| cpe:2.3:o:cisco:adaptive_security_appliance_software:9.14.1.15:*:*:*:*:*:*:* | 9.14.1.15 | Vulnerable | Cisco |
- cpe:2.3:a:cisco:secure_firewall_threat_defense:6.6.0.1:*:*:*:*:*:*:* Versions 6.6.0.1 Vulnerable ·Cisco
- cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.4.22:*:*:*:*:*:*:* Versions 9.8.4.22 Vulnerable ·Cisco
- cpe:2.3:o:cisco:adaptive_security_appliance_software:9.8.4.25:*:*:*:*:*:*:* Versions 9.8.4.25 Vulnerable ·Cisco
- cpe:2.3:o:cisco:adaptive_security_appliance_software:9.12.4.2:*:*:*:*:*:*:* Versions 9.12.4.2 Vulnerable ·Cisco
- cpe:2.3:o:cisco:adaptive_security_appliance_software:9.12.4.3:*:*:*:*:*:*:* Versions 9.12.4.3 Vulnerable ·Cisco
- cpe:2.3:o:cisco:adaptive_security_appliance_software:9.13.1.12:*:*:*:*:*:*:* Versions 9.13.1.12 Vulnerable ·Cisco
- cpe:2.3:o:cisco:adaptive_security_appliance_software:9.14.1.15:*:*:*:*:*:*:* Versions 9.14.1.15 Vulnerable ·Cisco
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2020-3373
- 2026-10-03 Alias added: GHSA-cjgx-rm4j-vw44
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-2020-3373 · CVE Program
- CVE-2020-3373 · NVD
- FIRST EPSS
- GHSA-cjgx-rm4j-vw44 · 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