Cisco Adaptive Security Appliance
CVE-2020-3555
A vulnerability in the SIP inspection process of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a crash and reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to a watchdog timeout and crash during the cleanup of threads that are associated with a SIP connection that is being deleted from the connection list. An attacker could exploit this vulnerability by sending a high rate of crafted SIP traffic through an affected device. A successful exploit could allow the attacker to cause a watchdog timeout and crash, resulting in a crash and reload of the affected device.
What this means for your business
- It affects Cisco Adaptive Security Appliance. 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
- 1Check whether your company or your suppliers run Cisco Adaptive Security Appliance, 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?
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Scoring
- CVSS
- 6.8 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H- Weakness
- CWE-404
- Assigned by
- psirt@cisco.com
Dates
- Published
- 2020-10-21
- Last modified
- 2026-08-11
- Sources
- NVD
Affected products
- Cisco Adaptive Security Appliance- 9.6.4.43
- Cisco Secure Firewall Threat Defense- 6.2.2, 6.3.0 - 6.3.0.6, 6.4.0 - 6.4.0.10, 6.5.0 - 6.5.0.5, 6.6.0
- Cisco Adaptive Security Appliance Software9.7.0 - 9.8.4.24, 9.9.0 - 9.9.2.80, 9.10.0 - 9.10.1.43, 9.12.0 - 9.12.4.2, 9.13.0 - 9.13.1.13, 9.14.0 - 9.14.1.19
As listed in the NVD configuration data. Not a statement about your estate.