CVE-2022-20655
📋 TL;DR
This vulnerability allows an authenticated local attacker to execute arbitrary commands with root privileges on devices running ConfD CLI due to insufficient input validation. It affects Cisco products using ConfD, requiring local access but posing high risk due to potential full system compromise. Exploitation could lead to complete control of the device.
💻 Affected Systems
- Cisco IOS XE Software
- Cisco Catalyst 9000 Series Switches
- Other Cisco devices using ConfD CLI
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Attacker gains root shell access, enabling data theft, system manipulation, or lateral movement across the network.
Likely Case
Privileged escalation leading to unauthorized configuration changes or persistence on the device.
If Mitigated
Limited impact if strict access controls and input validation are enforced, but risk remains if patched.
🎯 Exploit Status
Exploitation is straightforward for attackers with local credentials, but no public proof-of-concept is confirmed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Cisco Security Advisories for specific fixed versions (e.g., Cisco IOS XE 17.9.1 or later).
Vendor Advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cli-cmdinj-4MttWZPB
Restart Required: Yes
Instructions:
1. Review Cisco advisory for affected products. 2. Download and apply the recommended software update. 3. Reboot the device as required. 4. Verify the patch is installed.
🔧 Temporary Workarounds
Restrict Local Access
allLimit CLI access to trusted users only and enforce strong authentication.
configure terminal
username admin privilege 15 secret strongpassword
line console 0
login local
Disable Unnecessary CLI Features
allTurn off ConfD CLI if not required to reduce attack surface.
configure terminal
no confd cli
🧯 If You Can't Patch
- Implement strict access controls and monitor for suspicious CLI activity.
- Use network segmentation to isolate affected devices and limit potential lateral movement.
🔍 How to Verify
Check if Vulnerable:
Check the device version against Cisco's advisory; if running an affected version and ConfD CLI is enabled, it is vulnerable.Check Version:
show versionVerify Fix Applied:
Verify the software version has been updated to a patched release and confirm no command injection occurs in CLI processes.📡 Detection & Monitoring
Log Indicators:
- Unusual CLI command executions or error logs related to process arguments in ConfD.
Network Indicators:
- Anomalous outbound connections from the device post-CLI access.
SIEM Query:
source="device_logs" AND (event="CLI command injection" OR process="confd")