CVE-2021-1625 MEDIUM

CVE-2021-1625: Cisco IOS XE Software Zone-Based Policy Firewall ICMP and UDP Inspection Vulnerability

Vendor Cisco
Product Cisco IOS XE Software
Weakness CWE-284
Published September 23, 2021
Last update November 7, 2024

CVSS base score

5.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

What the vulnerability does

01Description

A vulnerability in the Zone-Based Policy Firewall feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to prevent the Zone-Based Policy Firewall from correctly classifying traffic. This vulnerability exists because ICMP and UDP responder-to-initiator flows are not inspected when the Zone-Based Policy Firewall has either Unified Threat Defense (UTD) or Application Quality of Experience (AppQoE) configured. An attacker could exploit this vulnerability by attempting to send UDP or ICMP flows through the network. A successful exploit could allow the attacker to inject traffic through the Zone-Based Policy Firewall, resulting in traffic being dropped because it is incorrectly classified or in incorrect reporting figures being produced by high-speed logging (HSL).

Key dates

02Disclosure timeline

September 23, 2021 CVE published
November 7, 2024 Record updated