CVE-2022-20759
📋 TL;DR
This vulnerability allows authenticated but unprivileged remote attackers to escalate privileges to level 15 (highest administrative level) on Cisco ASA and FTD devices via the web services interface. It affects remote access VPN features due to improper separation of authentication and authorization scopes. For FTD devices, the impact is limited to read-only access in the web management interface.
💻 Affected Systems
- Cisco Adaptive Security Appliance (ASA) Software
- Cisco Firepower Threat Defense (FTD) Software
📦 What is this software?
Adaptive Security Appliance Software by Cisco
View all CVEs affecting Adaptive Security Appliance Software →
Adaptive Security Appliance Software by Cisco
View all CVEs affecting Adaptive Security Appliance Software →
Adaptive Security Appliance Software by Cisco
View all CVEs affecting Adaptive Security Appliance Software →
Adaptive Security Appliance Software by Cisco
View all CVEs affecting Adaptive Security Appliance Software →
⚠️ Risk & Real-World Impact
Worst Case
Full administrative compromise of Cisco ASA devices, allowing complete control over firewall/VPN configurations, traffic inspection bypass, and potential network pivoting.
Likely Case
Privilege escalation to level 15 on ASA devices, enabling administrative access to web management interfaces and management tools like ASDM/CSM.
If Mitigated
Limited to read-only access on FTD devices, preventing configuration changes but potentially exposing sensitive information.
🎯 Exploit Status
Exploit requires authenticated access but minimal privileges. Crafted HTTPS messages to web services interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Multiple fixed versions available - refer to Cisco advisory
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-mgmt-privesc-BMFMUvye
Restart Required: Yes
Instructions:
1. Check current ASA/FTD version. 2. Review Cisco advisory for fixed versions. 3. Download and apply appropriate patch. 4. Reboot device. 5. Verify patch installation.
🔧 Temporary Workarounds
Disable web services interface
allDisable the vulnerable web services interface if not required for remote access VPN
no webvpn
no http server enable
Restrict access to management interfaces
allLimit access to web management interfaces to trusted IP addresses only
access-list management-access extended permit ip [trusted-network] any
http [ip-address] [subnet-mask] management-access
🧯 If You Can't Patch
- Implement strict network segmentation to isolate ASA/FTD management interfaces
- Enable multi-factor authentication and monitor for privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check ASA/FTD version against affected versions in Cisco advisory: show versionCheck Version:
show versionVerify Fix Applied:
Verify installed version matches fixed version from Cisco advisory: show version | include Version📡 Detection & Monitoring
Log Indicators:
- Unexpected privilege level changes in system logs
- Multiple authentication attempts from single user
- Access to administrative functions from low-privilege accounts
Network Indicators:
- HTTPS traffic to web services interface from unexpected sources
- Crafted HTTP POST requests to management endpoints
SIEM Query:
source="asa" OR source="ftd" AND (event_type="privilege_escalation" OR user_level_change="15")🔗 References
- https://github.com/orangecertcc/security-research/security/advisories/GHSA-gq88-gqmj-7v24
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-mgmt-privesc-BMFMUvye
- https://github.com/orangecertcc/security-research/security/advisories/GHSA-gq88-gqmj-7v24
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-mgmt-privesc-BMFMUvye
