Cisco Secure Firewall Threat Defense
CVE-2020-3179
A vulnerability in the generic routing encapsulation (GRE) tunnel decapsulation feature 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 a memory handling error when GRE over IPv6 traffic is processed. An attacker could exploit this vulnerability by sending crafted GRE over IPv6 packets with either IPv4 or IPv6 payload through an affected device. A successful exploit could allow the attacker to cause the device to crash, resulting in a DoS condition.
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.
- FIRST's prediction model gives it a 2% chance of attack attempts being seen in the next 30 days, ranking above 78% of all known flaws.
What to do
- 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.
- 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
- 7.5 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness
- CWE-415
- Assigned by
- psirt@cisco.com
Dates
- Published
- 2020-05-06
- Last modified
- 2026-08-11
- Sources
- NVD
Affected products
- Cisco Secure Firewall Threat Defense6.3.0 - 6.3.0.5, 6.4.0 - 6.4.0.6
- Cisco Asa 5505 Firmware9.9\(2\), 101.5\(1.26\)
- Cisco Asa 5505all versions
- Cisco Asa 5510 Firmware9.9\(2\), 101.5\(1.26\)
- Cisco Asa 5510all versions
- Cisco Asa 5512-X Firmware9.9\(2\), 101.5\(1.26\)
- Cisco Asa 5512-Xall versions
- Cisco Asa 5515-X Firmware9.9\(2\), 101.5\(1.26\)
- Cisco Asa 5515-Xall versions
- Cisco Asa 5520 Firmware9.9\(2\), 101.5\(1.26\)
- Cisco Asa 5520all versions
- Cisco Asa 5525-X Firmware9.9\(2\), 101.5\(1.26\)
As listed in the NVD configuration data. Not a statement about your estate.