Cisco ASA and FTD Denial of Service Vulnerability
- Severity
- High8.6CVSS 3.1, High
- EPSS
- 71%
- Published
- 24 Apr 2024
- Updated
- 11 Aug 2026
Description
Title, description and vendor guidance are quoted from the source records.
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.
Weakness: CWE-835
Known exploited
Added to CISA KEV on 24 Apr 2024
Federal remediation due date: 1 May 2024
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Exploit prediction
71% probability of exploitation in the next 30 days (percentile 99%).
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Affected products
Patcharo shows this vulnerability for information but does not match versions for this product yet.
- Cisco Cisco Adaptive Security Appliance (ASA) Software · 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 and 175 more
- Cisco Cisco Firepower Threat Defense Software · 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 and 68 more
References
- cisco-sa-asaftd-websrvs-dos-X8gNucD2(opens in a new tab)
- https://blog.talosintelligence.com/arcanedoor-new-espionage-focused-campaign-found-targeting-perimeter-network-devices/(opens in a new tab)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-20353(opens in a new tab)
Provenance
Every fact on this page comes from the sources below. Nothing is written by an AI.
- Cisco (CVE record)
- Cisco (CVE record) · 27 Sept 2026, 23:46 UTC · Parser patcharo-cve5/1.1.0
- CISA Known Exploited Vulnerabilities
- CISA Known Exploited Vulnerabilities · 27 Sept 2026, 23:42 UTC · Parser patcharo-kev/1.0.0
- NVD
- NVD · 27 Sept 2026, 23:44 UTC · Parser patcharo-nvd/1.0.0
- FIRST EPSS
- FIRST EPSS · 27 Sept 2026, 23:46 UTC · Parser patcharo-epss/1.0.0
Last verified: 28 Sept 2026, 02:31 UTC