Improper Resource Shutdown or Release in Cisco Adaptive Security Appliance (ASA) and Cisco Firewall Threat Defense (FTD) - CVE-2020-3555
Published: October 21, 2020 / Updated: October 27, 2020
Vulnerability identifier: #VU47945
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2020-3555
CWE-ID: CWE-404
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists 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. A remote attacker can send a high rate of specially crafted SIP traffic through an affected device and cause a denial of service condition on the target system.
Affected software
Cisco Adaptive Security Appliance (ASA)
Cisco Firewall Threat Defense (FTD)
Cisco Firewall Threat Defense (FTD)
How to mitigate CVE-2020-3555
Install update from vendor's website.
Cisco Adaptive Security Appliance (ASA) - addressed in versions 9.6.4.43, 9.8.4.26, 9.9.2.80, 9.10.1.43, 9.12.4.2
Cisco Firewall Threat Defense (FTD) - addressed in versions 6.3.0.6, 6.4.0.10, 6.5.0.5, 6.6.1
Cisco Firewall Threat Defense (FTD) - addressed in versions 6.3.0.6, 6.4.0.10, 6.5.0.5, 6.6.1