Performing Authenticated Scan with OpenVAS
Overview
OpenVAS (Open Vulnerability Assessment Scanner) is the scanner component of the Greenbone Vulnerability Management (GVM) framework. Authenticated scans use valid credentials (SSH for Linux, SMB for Windows, ESXi for VMware) to log into target systems, enabling detection of local vulnerabilities, missing patches, and misconfigurations that unauthenticated scans cannot identify. Authenticated scans typically find 10-50x more vulnerabilities than unauthenticated scans.
Prerequisites
- GVM 22.x+ installed (gvmd, openvas-scanner, gsad, ospd-openvas)
- PostgreSQL database configured for gvmd
- Redis configured for openvas-scanner
- NVT feed synchronized (greenbone-nvt-sync or greenbone-feed-sync)
- SSH credentials for Linux targets or SMB credentials for Windows targets
- Network access to target hosts on scan ports
Installation
Install GVM on Kali Linux / Debian
# Install GVM package
sudo apt update && sudo apt install -y gvm
# Run initial setup (creates admin account, syncs feeds)
sudo gvm-setup
# Check installation status
sudo gvm-check-setup
# Start all GVM services
sudo gvm-start
# Access Greenbone Security Assistant at https://127.0.0.1:9392
Install via Docker (Recommended for Production)
# Pull Greenbone Community Edition containers
docker pull greenbone/gvm:stable
# Run with docker-compose
curl -fsSL https://greenbone.github.io/docs/latest/_static/docker-compose-22.4.yml \
-o docker-compose.yml
# Start the stack
docker compose -f docker-compose.yml -p greenbone-community-edition up -d
# Wait for feed sync (initial sync takes 15-30 minutes)
docker compose -f docker-compose.yml -p greenbone-community-edition \
logs -f gvmd 2>&1 | grep -i "feed"
Configuring Credentials
SSH Credentials for Linux Targets
# Using gvm-cli to create SSH credential with key-based auth
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<create_credential>
<name>Linux SSH Key</name>
<type>usk</type>
<login>scan_user</login>
<key>
<private><![CDATA['"$(cat /home/scan_user/.ssh/id_rsa)"']]></private>
<phrase>key_passphrase</phrase>
</key>
</create_credential>'
# SSH credential with password authentication
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<create_credential>
<name>Linux SSH Password</name>
<type>up</type>
<login>scan_user</login>
<password>scan_password_here</password>
</create_credential>'
SMB Credentials for Windows Targets
# Create SMB credential for Windows authenticated scanning
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<create_credential>
<name>Windows SMB Cred</name>
<type>up</type>
<login>DOMAIN\scan_account</login>
<password>smb_password_here</password>
</create_credential>'
ESXi Credentials
# Create ESXi credential for VMware host scanning
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<create_credential>
<name>ESXi Root</name>
<type>up</type>
<login>root</login>
<password>esxi_password_here</password>
</create_credential>'
Creating Scan Targets
# Create target with SSH credential (Linux hosts)
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<create_target>
<name>Linux Production Servers</name>
<hosts>192.168.1.10,192.168.1.11,192.168.1.12</hosts>
<port_list id="33d0cd82-57c6-11e1-8ed1-406186ea4fc5"/>
<ssh_credential id="CREDENTIAL_UUID_HERE">
<port>22</port>
</ssh_credential>
<alive_test>ICMP, TCP-ACK Service and ARP Ping</alive_test>
</create_target>'
# Create target with SMB credential (Windows hosts)
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<create_target>
<name>Windows Domain Controllers</name>
<hosts>192.168.1.20,192.168.1.21</hosts>
<port_list id="33d0cd82-57c6-11e1-8ed1-406186ea4fc5"/>
<smb_credential id="SMB_CREDENTIAL_UUID_HERE"/>
<alive_test>ICMP, TCP-ACK Service and ARP Ping</alive_test>
</create_target>'
Scan Configuration
Built-in Scan Configs
| Config Name | OID | Use Case |
|---|---|---|
| Full and fast | daba56c8-73ec-11df-a475-002264764cea | Standard production scan |
| Full and deep | 708f25c4-7489-11df-8094-002264764cea | Thorough scan, may be disruptive |
| System Discovery | 8715c877-47a0-438d-98a3-27c7a6ab2196 | Host and service enumeration |
Create Custom Scan Config for Authenticated Scan
# Clone "Full and fast" config and customize
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<create_config>
<copy>daba56c8-73ec-11df-a475-002264764cea</copy>
<name>Authenticated Full Scan</name>
</create_config>'
Running the Scan
Create and Start Scan Task
# Create scan task
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<create_task>
<name>Weekly Authenticated Scan - Linux Prod</name>
<config id="CONFIG_UUID"/>
<target id="TARGET_UUID"/>
<scanner id="08b69003-5fc2-4037-a479-93b440211c73"/>
</create_task>'
# Start the scan task
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<start_task task_id="TASK_UUID"/>'
# Check scan progress
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<get_tasks task_id="TASK_UUID"/>'
Schedule Recurring Scans
# Create weekly schedule (every Sunday at 2:00 AM UTC)
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<create_schedule>
<name>Weekly Sunday 2AM</name>
<icalendar>
BEGIN:VCALENDAR
VERSION:2.0
BEGIN:VEVENT
DTSTART:20240101T020000Z
RRULE:FREQ=WEEKLY;BYDAY=SU
DURATION:PT12H
END:VEVENT
END:VCALENDAR
</icalendar>
<timezone>UTC</timezone>
</create_schedule>'
Exporting Results
# Export scan report as XML
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<get_reports report_id="REPORT_UUID" format_id="a994b278-1f62-11e1-96ac-406186ea4fc5"/>'
# Export as CSV
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<get_reports report_id="REPORT_UUID" format_id="c1645568-627a-11e3-a660-406186ea4fc5"/>'
# Use python-gvm for programmatic access
python3 -c "
from gvm.connections import UnixSocketConnection
from gvm.protocols.gmp import Gmp
from gvm.transforms import EtreeCheckCommandTransform
connection = UnixSocketConnection(path='/run/gvmd/gvmd.sock')
transform = EtreeCheckCommandTransform()
with Gmp(connection=connection, transform=transform) as gmp:
gmp.authenticate('admin', 'password')
reports = gmp.get_reports()
print(f'Total reports: {len(reports)}')
"
Validating Authentication Success
# Check if credentials were accepted during scan
# In the scan report, look for NVT "Authentication tests" results:
# - OID 1.3.6.1.4.1.25623.1.0.103591 (SSH authentication successful)
# - OID 1.3.6.1.4.1.25623.1.0.90023 (SMB authentication successful)
# Verify via gvm-cli
gvm-cli socket --socketpath /run/gvmd/gvmd.sock --gmp-username admin --gmp-password <password> --xml \
'<get_results filter="name=SSH rows=10 sort-reverse=severity"/>'
Compliance Framework Mapping
This skill supports compliance evidence collection across multiple frameworks:
- SOC 2: CC7.1 (Monitoring), CC8.1 (Change Management)
- ISO 27001: A.12.6 (Technical Vulnerability Management)
- NIST 800-53: RA-5 (Vulnerability Scanning), SI-2 (Flaw Remediation), CM-6 (Configuration Settings)
- NIST CSF: ID.RA (Risk Assessment), PR.IP (Information Protection)
Claw GRC Tip: When this skill is executed by a registered agent, compliance evidence is automatically captured and mapped to the relevant controls in your active frameworks.
Deploying This Skill with Claw GRC
Agent Execution
Register this skill with your Claw GRC agent for automated execution:
# Install via CLI
npx claw-grc skills add performing-authenticated-scan-with-openvas
# Or load dynamically via MCP
grc.load_skill("performing-authenticated-scan-with-openvas")
Audit Trail Integration
When executed through Claw GRC, every step of this skill generates tamper-evident audit records:
- SHA-256 chain hashing ensures no step can be modified after execution
- Evidence artifacts (configs, scan results, logs) are automatically attached to relevant controls
- Trust score impact — successful execution increases your agent's trust score
Continuous Compliance
Schedule this skill for recurring execution to maintain continuous compliance posture. Claw GRC monitors for drift and alerts when re-execution is needed.