CVE-2021-1625: Cisco IOS XE Software Zone-Based Policy Firewall ICMP and UDP Inspection Vulnerability
First published: Thu Sep 23 2021(Updated: )
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).
Credit: ykramarz@cisco.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Cisco IOS XE Web UI | <17.3.2 |
Never miss a vulnerability like this again
Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.
Reference Links
Frequently Asked Questions
What is the severity of CVE-2021-1625?
CVE-2021-1625 has a high severity rating due to its potential impact on traffic classification by the Zone-Based Policy Firewall.
How do I fix CVE-2021-1625?
To fix CVE-2021-1625, update Cisco IOS XE Software to version 17.3.3 or later.
What types of attacks could be executed using CVE-2021-1625?
An attacker could exploit CVE-2021-1625 to disrupt the Zone-Based Policy Firewall's traffic classification, potentially leading to unauthorized traffic flow.
Which versions of Cisco IOS XE software are affected by CVE-2021-1625?
Cisco IOS XE versions up to 17.3.2 are affected by CVE-2021-1625.
Is authentication required to exploit CVE-2021-1625?
No, CVE-2021-1625 can be exploited by unauthenticated remote attackers.
- agent/type
- agent/softwarecombine
- agent/author
- agent/weakness
- agent/title
- agent/references
- agent/severity
- agent/description
- agent/first-publish-date
- agent/event
- collector/mitre-cve
- source/MITRE
- agent/last-modified-date
- agent/source
- agent/tags
- collector/nvd-index
- agent/software-canonical-lookup-request
- vendor/cisco
- canonical/cisco ios xe web ui