CVE-2021-1622: Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers Common Open Policy Service Denial of Service Vulnerability

Severity: high (CVSS 8.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-09-23 · updated 2026-06-17
Weakness: CWE-833

Description

A vulnerability in the Common Open Policy Service (COPS) of Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, remote attacker to cause resource exhaustion, resulting in a denial of service (DoS) condition. This vulnerability is due to a deadlock condition in the code when processing COPS packets under certain conditions. An attacker could exploit this vulnerability by sending COPS packets with high burst rates to an affected device. A successful exploit could allow the attacker to cause the CPU to consume excessive resources, which prevents other control plane processes from obtaining resources and results in a DoS.

Affected products

Cisco IOS XE: before 16.12.1z1; 17.3.1x — fixed in 16.12.1z1

How to fix

Upgrade to a fixed version: Cisco IOS XE 16.12.1z1. Check the vendor advisory for mitigations.

References

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