CVE-2024-20353Cisco ASA and FTD Denial of Service Vulnerability

A vulnerability in the management and VPN web servers for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to incomplete error checking when parsing an HTTP header. An attacker could exploit this vulnerability by sending a crafted HTTP request to a targeted web server on a device. A successful exploit could allow the attacker to cause a DoS condition when the device reloads.

8.6 HIGHEPSS 69.82%⚡ Known Exploited (CISA KEV)NVD: Analyzed

Last updated: 2026-08-11 19:33 UTC

Overview Affected Products References

NVD CVE.org

Overview

Severity

Score	Severity	Version	Vector String
8.6	HIGH	3.1cisco (CNA)	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CISA required action

⚡ Known exploited · remediation due May 1, 2024

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Details

CVE ID: CVE-2024-20353
Status: Analyzed
Assigner (CNA): cisco
Published: Apr 24, 2024
Last modified: 2026-08-11 19:33 UTC
Weaknesses: CWE-835 · Loop with Unreachable Exit Condition ('Infinite Loop')

Affected Products

As published by the CNA in the CVE record.

CiscoCisco Adaptive Security Appliance (ASA) Software187 version ranges

9.8.1
9.8.1.5
9.8.1.7
9.8.2
9.8.2.8
9.8.2.14
9.8.2.15
9.8.2.17
9.8.2.20
9.8.2.24
9.8.2.26
9.8.2.28
9.8.2.33
9.8.2.35
9.8.2.38
9.8.3.8
9.8.3.11
9.8.3.14
9.8.3.16
9.8.3.18
9.8.3.21
9.8.3
9.8.3.26
9.8.3.29
9.8.4
9.8.4.3
9.8.4.7
9.8.4.8
9.8.4.10
9.8.4.12
9.8.4.15
9.8.4.17
9.8.4.25
9.8.4.20
9.8.4.22
9.8.4.26
9.8.4.29
9.8.4.32
9.8.4.33
9.8.4.34
9.8.4.35
9.8.4.39
9.8.4.40
9.8.4.41
9.8.4.43
9.8.4.44
9.8.4.45
9.8.4.46
9.8.4.48
9.12.1
9.12.1.2
9.12.1.3
9.12.2
9.12.2.4
9.12.2.5
9.12.2.9
9.12.3
9.12.3.2
9.12.3.7
9.12.4
9.12.3.12
9.12.3.9
9.12.2.1
9.12.4.2
9.12.4.4
9.12.4.7
9.12.4.10
9.12.4.13
9.12.4.8
9.12.4.18
9.12.4.24
9.12.4.26
9.12.4.29
9.12.4.30
9.12.4.35
9.12.4.37
9.12.4.38
9.12.4.39
9.12.4.40
9.12.4.41
9.12.4.47
9.12.4.48
9.12.4.50
9.12.4.52
9.12.4.54
9.12.4.55
9.12.4.56
9.12.4.58
9.12.4.62
9.12.4.65
9.14.1
9.14.1.10
9.14.1.6
9.14.1.15
9.14.1.19
9.14.1.30
9.14.2
9.14.2.4
9.14.2.8
9.14.2.13
9.14.2.15
9.14.3
9.14.3.1
9.14.3.9
9.14.3.11
9.14.3.13
9.14.3.18
9.14.3.15
9.14.4
9.14.4.6
9.14.4.7
9.14.4.12
9.14.4.13
9.14.4.14
9.14.4.15
9.14.4.17
9.14.4.22
9.14.4.23
9.15.1
9.15.1.7
9.15.1.10
9.15.1.15
9.15.1.16
9.15.1.17
9.15.1.1
9.15.1.21
9.16.1
9.16.1.28
9.16.2
9.16.2.3
9.16.2.7
9.16.2.11
9.16.2.13
9.16.2.14
9.16.3
9.16.3.3
9.16.3.14
9.16.3.15
9.16.3.19
9.16.3.23
9.16.4
9.16.4.9
9.16.4.14
9.16.4.18
9.16.4.19
9.16.4.27
9.16.4.38
9.16.4.39
9.16.4.42
9.16.4.48
9.16.4.55
9.17.1
9.17.1.7
9.17.1.9
9.17.1.10
9.17.1.11
9.17.1.13
9.17.1.15
9.17.1.20
9.17.1.30
9.17.1.33
9.18.1
9.18.1.3
9.18.2
9.18.2.5
9.18.2.7
9.18.2.8
9.18.3
9.18.3.39
9.18.3.46
9.18.3.53
9.18.3.55
9.18.3.56
9.18.4
9.18.4.5
9.18.4.8
9.19.1
9.19.1.5
9.19.1.9
9.19.1.12
9.19.1.18
9.19.1.22
9.19.1.24
9.19.1.27
9.20.1
9.20.1.5
9.20.2

CiscoCisco Firepower Threat Defense Software80 version ranges

6.2.3
6.2.3.1
6.2.3.2
6.2.3.3
6.2.3.4
6.2.3.5
6.2.3.6
6.2.3.7
6.2.3.8
6.2.3.10
6.2.3.11
6.2.3.9
6.2.3.12
6.2.3.13
6.2.3.14
6.2.3.15
6.2.3.16
6.2.3.17
6.2.3.18
6.6.0
6.6.0.1
6.6.1
6.6.3
6.6.4
6.6.5
6.6.5.1
6.6.5.2
6.6.7
6.6.7.1
6.4.0
6.4.0.1
6.4.0.3
6.4.0.2
6.4.0.4
6.4.0.5
6.4.0.6
6.4.0.7
6.4.0.8
6.4.0.9
6.4.0.10
6.4.0.11
6.4.0.12
6.4.0.13
6.4.0.14
6.4.0.15
6.4.0.16
6.4.0.17
6.7.0
6.7.0.1
6.7.0.2
6.7.0.3
7.0.0
7.0.0.1
7.0.1
7.0.1.1
7.0.2
7.0.2.1
7.0.3
7.0.4
7.0.5
7.0.6
7.0.6.1
7.1.0
7.1.0.1
7.1.0.2
7.1.0.3
7.2.0
7.2.0.1
7.2.1
7.2.2
7.2.3
7.2.4
7.2.4.1
7.2.5
7.2.5.1
7.3.0
7.3.1
7.3.1.1
7.4.0
7.4.1

Sources

Refreshed hourly from the sources above. Last fetched 2026-11-08 13:26 UTC.