Secure Firewall ASA and FTD
CVE-2024-20353: ASA and FTD Denial of Service
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.
Published
ExploitedYes, in CISA KEVAdded 24 Apr 2024
Ransomware useNot reportedPer CISA
SeverityHIGHCVSS 3.1 8.6
EPSS71%Chance of exploitation in 30 days
Public exploitNot tracked
FixNot yet
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.8 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.12 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.14 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.15 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.15 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.15 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.15 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.15 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.15 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.15 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.15 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.16 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.17 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.17 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.17 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.17 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.17 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.17 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.17 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.17 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.17 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.17 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.18 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.19 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.19 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.19 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.19 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.19 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.19 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.19 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.19 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.20 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.20 | See the advisory |
| Cisco Adaptive Security Appliance (ASA) Software 9.20 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.2 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.6 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.4 | See the advisory |
| Cisco Firepower Threat Defense Software 6.7 | See the advisory |
| Cisco Firepower Threat Defense Software 6.7 | See the advisory |
| Cisco Firepower Threat Defense Software 6.7 | See the advisory |
| Cisco Firepower Threat Defense Software 6.7 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.0 | See the advisory |
| Cisco Firepower Threat Defense Software 7.1 | See the advisory |
| Cisco Firepower Threat Defense Software 7.1 | See the advisory |
| Cisco Firepower Threat Defense Software 7.1 | See the advisory |
| Cisco Firepower Threat Defense Software 7.1 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.2 | See the advisory |
| Cisco Firepower Threat Defense Software 7.3 | See the advisory |
| Cisco Firepower Threat Defense Software 7.3 | See the advisory |
| Cisco Firepower Threat Defense Software 7.3 | See the advisory |
| Cisco Firepower Threat Defense Software 7.4 | See the advisory |
| Cisco Firepower Threat Defense Software 7.4 | See the advisory |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
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.
Exploitation
Cisco has confirmed that this vulnerability has been exploited. Cisco strongly recommends that customers upgrade to fixed software to resolve this vulnerability. Customers are also strongly encouraged to monitor system logs for indicators of undocumented configuration changes, unscheduled reboots, and any anomalous credential activity.
CISA lists this CVE as exploited in the wild since 24 Apr 2024.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 11 Oct 2026.