CVE-2020-3305: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software BGP Denial of Service Vulnerability

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-05-06 · updated 2026-08-11
Weakness: CWE-400

Description

A vulnerability in the implementation of the Border Gateway Protocol (BGP) module in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of certain BGP packets. An attacker could exploit this vulnerability by sending a crafted BGP packet. A successful exploit could allow the attacker to cause a DoS condition on the affected device.

Affected products

Cisco Adaptive Security Appliance: before 9.6.4.36 — fixed in 9.6.4.36
Cisco ASA Software: from 9.7 before 9.8.4.10; from 9.9 before 9.10.1.30; from 9.12 before 9.12.2.9 — fixed in 9.10.1.30, 9.12.2.9, 9.8.4.10
Cisco Firepower Threat Defense Software: before 6.3.0.5; from 6.4.0 before 6.4.0.6 — fixed in 6.3.0.5, 6.4.0.6

How to fix

Upgrade to a fixed version: Cisco Adaptive Security Appliance 9.6.4.36; Cisco ASA Software 9.10.1.30, 9.12.2.9, 9.8.4.10; Cisco Firepower Threat Defense Software 6.3.0.5, 6.4.0.6. Check the vendor advisory for mitigations.

References

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