CVE-2021-1623: Cisco IOS XE

High severity, CVSS 7.7. EPSS: 1.1% chance of exploitation in the next 30 days.

A vulnerability in the Simple Network Management Protocol (SNMP) punt handling function of Cisco cBR-8 Converged Broadband Routers could allow an authenticated, remote attacker to overload a device punt path, resulting in a denial of service (DoS) condition. This vulnerability is due to the punt path being overwhelmed by large quantities of SNMP requests. An attacker could exploit this vulnerability by sending a large number of SNMP requests to an affected device. A successful exploit could allow the attacker to overload the device punt path, resulting in a DoS condition.

Affected products

• Cisco IOS XE: before 17.6.1a (fixed in 17.6.1a)

Published 2021-09-23. Last modified 2026-06-17.