CVE-2022-20829
📋 TL;DR
This vulnerability allows authenticated administrators to upload malicious ASDM images to Cisco ASA devices, which can execute arbitrary code on the computers of users who connect to the device using ASDM. Only administrators with device access and users who manage the same device using ASDM are affected. Cisco has released patches to address this insufficient image validation issue.
💻 Affected Systems
- Cisco Adaptive Security Appliance (ASA) Software
- Cisco Adaptive Security Device Manager (ASDM)
📦 What is this software?
Adaptive Security Device Manager by Cisco
⚠️ Risk & Real-World Impact
Worst Case
An attacker with administrative access could compromise all ASDM users' workstations, leading to full network compromise, data theft, and lateral movement.
Likely Case
Privileged insider or compromised admin account could target specific administrators' workstations for credential theft or persistence.
If Mitigated
With proper access controls and monitoring, impact is limited to targeted user workstations rather than network-wide compromise.
🎯 Exploit Status
Exploitation requires administrative privileges on the ASA device. Public proof-of-concept code exists in the 'theway' repository.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Cisco ASA Software releases 9.16.2.20, 9.17.2.10, 9.18.3.10, 9.19.1.10 and later
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-asdm-sig-NPKvwDjm
Restart Required: Yes
Instructions:
1. Download the patched ASA software version from Cisco. 2. Upload to the ASA device. 3. Install the update following Cisco's upgrade procedures. 4. Reboot the ASA device.
🔧 Temporary Workarounds
Restrict ASDM Image Uploads
allLimit administrative access to only trusted personnel and monitor ASDM image upload activities.
# Configure strict access controls for administrative interfaces
# Implement change management for ASDM image updates
Disable ASDM Management
allUse alternative management methods (CLI, other management tools) instead of ASDM.
# Remove ASDM image from ASA: no asdm image disk0:/asdm-xxx.bin
# Disable ASDM access: no http server enable
🧯 If You Can't Patch
- Implement strict administrative access controls and multi-factor authentication
- Monitor and audit all ASDM image upload activities and administrative sessions
🔍 How to Verify
Check if Vulnerable:
Check ASA software version with 'show version' and compare against affected versions list.Check Version:
show version | include SoftwareVerify Fix Applied:
Verify ASA software version is 9.16.2.20, 9.17.2.10, 9.18.3.10, 9.19.1.10 or later using 'show version'.📡 Detection & Monitoring
Log Indicators:
- ASDM image upload events
- Administrative session from unusual IP addresses
- ASDM installation logs
Network Indicators:
- Unusual ASDM traffic patterns
- ASDM connections from unexpected sources
SIEM Query:
source="asa" AND (event_type="ASDM_IMAGE_UPLOAD" OR cmd="copy" AND filename="*.bin")🔗 References
- https://github.com/jbaines-r7/theway
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-asdm-sig-NPKvwDjm
- https://www.rapid7.com/blog/post/2022/08/11/rapid7-discovered-vulnerabilities-in-cisco-asa-asdm-and-firepower-services-software/
- https://github.com/jbaines-r7/theway
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-asdm-sig-NPKvwDjm
- https://www.rapid7.com/blog/post/2022/08/11/rapid7-discovered-vulnerabilities-in-cisco-asa-asdm-and-firepower-services-software/
