Input validation error in Cisco IOS and Cisco IOS XE - CVE-2021-1620
Published: September 23, 2021
Vulnerability identifier: #VU56842
CSH Severity: Medium
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-1620
CWE-ID: CWE-20
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 the code does not release the allocated IP address under certain failure conditions in the Internet Key Exchange Version 2 (IKEv2) support for the AutoReconnect feature. A remote authenticated attacker can try to connect to the device with a non-AnyConnect client and perform a denial of service (DoS) attack.
Affected software
Cisco IOS
Cisco IOS XE
Cisco IOS XE
How to mitigate CVE-2021-1620
Install updates from vendor's website.
Cisco IOS - addressed in versions 16.9.8, 16.12.6, 17.3.4, 17.5.1, 17.6.1
Cisco IOS XE - addressed in versions 16.9.8, 16.12.6, 17.3.4, 17.5.1, 17.6.1
Cisco IOS XE - addressed in versions 16.9.8, 16.12.6, 17.3.4, 17.5.1, 17.6.1