CVE-2022-20622
📋 TL;DR
This vulnerability allows unauthenticated remote attackers to cause Cisco Embedded Wireless Controllers with Catalyst Access Points to reload unexpectedly by flooding the management interface with IP packets, resulting in denial of service. The vulnerability affects Cisco wireless infrastructure devices due to improper rate limiting. Organizations using affected Cisco wireless controllers and access points are at risk.
💻 Affected Systems
- Cisco Embedded Wireless Controller with Catalyst Access Points
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device outage with extended downtime, disrupting all wireless network services and requiring manual intervention to restore functionality.
Likely Case
Intermittent service disruptions, degraded wireless performance, and potential cascading failures in wireless networks during attack periods.
If Mitigated
Minimal impact with proper network segmentation and rate limiting controls in place, though some performance degradation may still occur during attacks.
🎯 Exploit Status
Exploitation requires only the ability to send high-rate IP traffic to the management interface, making it relatively simple to execute.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Cisco IOS XE Software Release 17.9.1 and later
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ap-ip-flood-dos-6hxxENVQ
Restart Required: Yes
Instructions:
1. Download the patched software from Cisco's software download center. 2. Backup current configuration. 3. Upgrade to Cisco IOS XE Software Release 17.9.1 or later. 4. Reboot the device to apply the update.
🔧 Temporary Workarounds
Implement Access Control Lists
allRestrict access to the management interface using ACLs to limit which IP addresses can communicate with it.
ip access-list extended MGMT-ACL
permit ip host [trusted_ip] any
deny ip any any
interface [management_interface]
ip access-group MGMT-ACL in
Rate Limiting Configuration
allConfigure rate limiting on the management interface to restrict packet processing rates.
interface [management_interface]
rate-limit input [rate] [burst] conform-action transmit exceed-action drop
🧯 If You Can't Patch
- Segment the management network to restrict access only to authorized administrative systems.
- Implement network-based rate limiting using firewalls or intrusion prevention systems to filter traffic to management interfaces.
🔍 How to Verify
Check if Vulnerable:
Check the Cisco IOS XE software version using 'show version' command and compare against affected versions listed in the Cisco advisory.Check Version:
show version | include VersionVerify Fix Applied:
Verify the software version is 17.9.1 or later using 'show version' command and check that management interface ACLs or rate limiting are properly configured.📡 Detection & Monitoring
Log Indicators:
- High CPU utilization alerts
- Unexpected device reloads
- Management interface packet flood warnings
- Rate limiting violation logs
Network Indicators:
- Unusual high-rate traffic to management IP addresses
- ICMP/UDP/TCP floods targeting management interfaces
- Sudden drops in wireless controller responsiveness
SIEM Query:
source="cisco_wlc" AND (message="*reload*" OR message="*CPU*high*" OR message="*flood*" OR message="*rate limit*")