CVE-2020-3191

HIGH

Cisco ASA and Firepower Threat Defense - Denial of Service via IPv6 DNS Packet Length Validation

Title source: llm
STIX 2.1

Description

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.

References (1)

Core 1
Core References

Scores

CVSS v3 8.6
EPSS 0.0104
EPSS Percentile 77.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-20
Status published
Products (26)
cisco/adaptive_security_appliance_software 9.6 - 9.6.4.36
cisco/asa_5505_firmware 9.4\(1\)
cisco/asa_5505_firmware 96.4\(0.42\)
cisco/asa_5510_firmware 9.4\(1\)
cisco/asa_5510_firmware 96.4\(0.42\)
cisco/asa_5512-x_firmware 9.4\(1\)
cisco/asa_5512-x_firmware 96.4\(0.42\)
cisco/asa_5515-x_firmware 9.4\(1\)
cisco/asa_5515-x_firmware 96.4\(0.42\)
cisco/asa_5520_firmware 9.4\(1\)
... and 16 more
Published May 06, 2020
Tracked Since Feb 18, 2026