Cisco Firepower Threat Defense Software SNMP Denial of Service 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 Simple Network Management Protocol (SNMP) input packet processor of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to restart unexpectedly. The vulnerability is due to a lack of sufficient memory management protections under heavy SNMP polling loads. An attacker could exploit this vulnerability by sending a high rate of SNMP requests to the SNMP daemon through the management interface on an affected device. A successful exploit could allow the attacker to cause the SNMP daemon process to consume a large amount of system memory over time, which could then lead to an unexpected device restart, causing a denial of service (DoS) condition. This vulnerability affects all versions of SNMP.
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 Firepower Threat Defense Software | all versions | — | No fix listed | CNA |
- Cisco Firepower Threat Defense Software VendorCisco Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:* | before 6.3.0.6; 6.4.0 to before 6.4.0.10; 6.5.0 to before 6.5.0.5; 6.6.0 to before 6.6.1 | Vulnerable | Cisco |
- cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:* Versions before 6.3.0.6; 6.4.0 to before 6.4.0.10; 6.5.0 to before 6.5.0.5; 6.6.0 to before 6.6.1 Vulnerable ·Cisco
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2020-3533
- 2026-10-03 Alias added: GHSA-78fc-hxwx-qqwj
References
More Cisco Secure Firewall Threat Defense vulnerabilities
- TI-2025-14628 Buffer overflow in Cisco Secure Firewall Adaptive Security Appliance Software KEVCVSS 3.1CRITICAL 9.9
- TI-2021-19919 Apache Log4j2 JNDI features do not protect against attacker controlled LDAP and other JNDI related endpoints KEVCVSS 3.1CRITICAL 10.0
- 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-2020-3533 · CVE Program
- CVE-2020-3533 · NVD
- FIRST EPSS
- GHSA-78fc-hxwx-qqwj · 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