CVE-2021-1624

HIGH

Cisco IOS XE < 17.3.3 - Unauthenticated Denial of Service via Rate Limiting NAT Feature

Title source: llm
STIX 2.1

Description

A vulnerability in the Rate Limiting Network Address Translation (NAT) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause high CPU utilization in the Cisco QuantumFlow Processor of an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to mishandling of the rate limiting feature within the QuantumFlow Processor. An attacker could exploit this vulnerability by sending large amounts of traffic that would be subject to NAT and rate limiting through an affected device. A successful exploit could allow the attacker to cause the QuantumFlow Processor utilization to reach 100 percent on the affected device, resulting in a DoS condition.

References (1)

Core 1
Core References

Scores

CVSS v3 8.6
EPSS 0.0042
EPSS Percentile 61.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-399
Status published
Products (1)
cisco/ios_xe < 17.3.3
Published Sep 23, 2021
Tracked Since Feb 18, 2026