CVE-2020-3306

Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software DHCP Denial of Service Vulnerability

HIGH

7.5

CVSS Score

Published: May 6, 2020 at 04:42 PM UTC

Updated: August 11, 2026 at 07:37 PM UTC

12 products affected across 1 vendorAdaptive Security ApplianceSecure Firewall Threat DefenseASA 5580

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Severity

HIGH7.5

Exploit prediction

EPSS 1%

SSVC

No known exploit

Description

A vulnerability in the DHCP module of 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 on the affected device. The vulnerability is due to incorrect processing of certain DHCP packets. An attacker could exploit this vulnerability by sending a crafted DHCP packet to the affected device. A successful exploit could allow the attacker to cause a DoS condition on the affected device.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Adaptive Security Appliance · Cisco

95%

v < 9.6.4.349.12 ≤ v < 9.12.39.7 ≤ v < 9.8.4.109.9 ≤ v < 9.10.1.30

Affected range stops below 9.10.1.30, so it looks safe — our inference, not a vendor statement

Affected range stops below 9.12.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 9.6.4.34, so it looks safe — our inference, not a vendor statement

Affected range stops below 9.8.4.10, so it looks safe — our inference, not a vendor statement

cisco-asa-5505 (environment) · cisco-asa-5510 (environment) · cisco-asa-5512-x (environment) · cisco-asa-5515-x (environment) · cisco-asa-5520 (environment) · cisco-asa-5525-x (environment) · cisco-asa-5550 (environment) · cisco-asa-5555-x (environment) · cisco-asa-5580 (environment) · cisco-asa-5585-x (environment)

Secure Firewall Threat Defense · Cisco

95%

v < 6.3.0.56.4.0 ≤ v < 6.4.0.4

ASA 5505 · Ciscodevice

80%

All versions

ASA 5510 · Ciscodevice

80%

All versions

Asa 5512-X · Ciscodevice

80%

All versions