CVE-2020-3563: high-severity vulnerability in Cisco Firepower Threat Defense Software
Cisco Firepower Threat Defense Software TCP Flood Denial of Service Vulnerability
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.6epss 1.4%
A vulnerability in the packet processing functionality of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to inefficient memory management. An attacker could exploit this vulnerability by sending a large number of TCP packets to a specific port on an affected device. A successful exploit could allow the attacker to exhaust system memory, which could cause the device to reload unexpectedly. No manual intervention is needed to recover the device after it has reloaded.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Affected products
Cisco · Cisco Firepower Threat Defense SoftwareRelated CVEs — Cisco Firepower Threat Defense Software
In the same product, most dangerous first.
CVE-2024-20353HIGHCVE-2024-20353EPSS 69.8%KEVCVE-2023-20269MEDIUMCVE-2023-20269EPSS 26.6%KEVCVE-2024-20359MEDIUMCVE-2024-20359EPSS 18.8%KEVCVE-2024-20481MEDIUMCVE-2024-20481EPSS 15.9%KEVCVE-2019-1978MEDIUMCisco Firepower Threat Defense Software Stream Reassembly Bypass VulnerabilityEPSS 9.4%CVE-2025-20363CRITICALCVE-2025-20363EPSS 7.2%