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

published 2020-10-21 6 y ago modified 2026-08-11 2 mo ago also EUVD-2020-24575

cvss: 8.6; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 3.9%; EPSS 3.9% chance of exploitation in 30 days, percentile 90%
public exploits: 0; none known

A vulnerability in the web interface of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. The vulnerability is due to a lack of proper input validation of HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. An exploit could allow the attacker to cause a DoS condition. Note: This vulnerability applies to IP Version 4 (IPv4) and IP Version 6 (IPv6) HTTP traffic.

Patch / fix

fixed in 3

cisco adaptive_security_appliance 9.6.4.45
cisco secure_firewall_threat_defense 6.3.0.6, 6.4.0.10, 6.5.0.5, 6.6.1
cisco adaptive_security_appliance_software 9.8.4.22, 9.9.2.80, 9.10.1.44, 9.12.3.12, 9.13.1.12, 9.14.1.10

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 23 mo ago (2024-11-13)

Exploit prediction

3.86% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.0	8.6	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD	3.1	8.6	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD	2.0	7.8	AV:N/AC:L/Au:N/C:N/I:N/A:C

Affected products

Cisco Cisco Adaptive Security Appliance (ASA) Software

Classification

Weakness

CWE-400 Uncontrolled Resource Consumption
CWE-20 Improper Input Validation

References

tools.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-webdos-fBzM5Ynw
vendor-advisory

Sources

CVE List CVE-2020-3304
NVD CVE-2020-3304

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Summary