CVE-2020-3255
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.
Does this matter?
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.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 1.86% probability · 79th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- 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
- Source
- psirt@cisco.com
EPSS 1.9% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.