CVE-2021-1620: cisco cisco_ios Assignment to Variable without Use

Vulnerability summary

CVE-2021-1620 is a high (CVSS 7.7) Assignment to Variable without Use vulnerability in cisco cisco_ios. EPSS estimates a 1.07% chance of exploitation in the next 30 days, higher than 64.2% of scored vulnerabilities.

Timeline

1. 23-09-2021
   PublishedVulnerability first disclosed.
2. 07-11-2024
   Last modifiedVulnerability information updated.

Description

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) support for the AutoReconnect feature of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to exhaust the free IP addresses from the assigned local pool. This vulnerability occurs because the code does not release the allocated IP address under certain failure conditions. An attacker could exploit this vulnerability by trying to connect to the device with a non-AnyConnect client. A successful exploit could allow the attacker to exhaust the IP addresses from the assigned local pool, which prevents users from logging in and leads to a denial of service (DoS) condition.

• CWE-563Assignment to Variable without UseThe variable's value is assigned but never used, making it a dead store.
• CWE-772Missing Release of Resource after Effective LifetimeThe product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.