{"id":"CVE-2020-3255","url":"https://www.cyber-defence.io/tools/cve/CVE-2020-3255","generatedAt":"2026-10-27T21:17:30.174Z","title":"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.","description":"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 high rate of IPv4 or IPv6 traffic through an affected device. This traffic would need to match a configured block action in an access control policy. An exploit could allow the attacker to cause a memory exhaustion condition on the affected device, which would result in a DoS for traffic transiting the device, as well as sluggish performance of the management interface. Once the flood is stopped, performance should return to previous states.","published":"2020-05-06T17:15:13.000Z","lastModified":"2026-08-11T19:33:45.000Z","status":"Modified","sourceIdentifier":"psirt@cisco.com","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-400"],"affected":["cisco/secure firewall threat defense","cisco/asa 5505 firmware","cisco/asa 5510 firmware","cisco/asa 5512-x firmware","cisco/asa 5515-x firmware","cisco/asa 5520 firmware","cisco/asa 5525-x firmware","cisco/asa 5540 firmware","cisco/asa 5545-x firmware","cisco/asa 5550 firmware","cisco/asa 5555-x firmware","cisco/asa 5580 firmware","cisco/asa 5585-x firmware"],"epss":{"score":0.01856,"percentile":0.79031,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (1.86%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-dos-N2vQZASR","tags":["Vendor Advisory"],"source":"psirt@cisco.com"},{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-dos-N2vQZASR","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2020-3255","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}