5.3Medium

Cisco Secure Firewall Threat Defense

CVE-2020-3188

A vulnerability in how Cisco Firepower Threat Defense (FTD) Software handles session timeouts for management connections could allow an unauthenticated, remote attacker to cause a buildup of remote management connections to an affected device, which could result in a denial of service (DoS) condition. The vulnerability exists because the default session timeout period for specific to-the-box remote management connections is too long. An attacker could exploit this vulnerability by sending a large and sustained number of crafted remote management connections to an affected device, resulting in a buildup of those connections over time. A successful exploit could allow the attacker to cause the remote management interface or Cisco Firepower Device Manager (FDM) to stop responding and cause other management functions to go offline, resulting in a DoS condition. The user traffic that is flowing through the device would not be affected, and the DoS condition would be isolated to remote management only.

What this means for your business

  • It affects Cisco Secure Firewall Threat Defense. It matters if your company, or a supplier that handles your data, runs it.
  • An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.

What to do

  1. 1Check whether your company or your suppliers run Cisco Secure Firewall Threat Defense, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
5.3 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness
CWE-399
Assigned by
psirt@cisco.com

Dates

Published
2020-05-06
Last modified
2026-08-11
Sources
NVD

Affected products

  • Cisco Secure Firewall Threat Defense6.4.0 - 6.4.0.9, 6.5.0 - 6.5.0.5
  • Cisco Asa 5505 Firmware9.8\(3\), 101.6\(1.96\)
  • Cisco Asa 5505all versions
  • Cisco Asa 5510 Firmware9.8\(3\), 101.6\(1.96\)
  • Cisco Asa 5510all versions
  • Cisco Asa 5512-X Firmware9.8\(3\), 101.6\(1.96\)
  • Cisco Asa 5512-Xall versions
  • Cisco Asa 5515-X Firmware9.8\(3\), 101.6\(1.96\)
  • Cisco Asa 5515-Xall versions
  • Cisco Asa 5520 Firmware9.8\(3\), 101.6\(1.96\)
  • Cisco Asa 5520all versions
  • Cisco Asa 5525-X Firmware9.8\(3\), 101.6\(1.96\)

As listed in the NVD configuration data. Not a statement about your estate.

References