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/learning/tools/openvas-greenbone-ce :: tool-guide-6

defender@hack3rs:~/learning/tools$ open openvas-greenbone-ce

OpenVAS / Greenbone CE

Vulnerability management

OpenVAS / Greenbone Community Edition provides a community-driven vulnerability management stack for recurring scanning and remediation workflows. It is a strong learning platform for understanding how scanners support defense operations.

how-to-learn-this-tool-like-a-defender

Study the tool in layers: first what problem it solves, then how to run it safely, then how to interpret output, and finally how to combine it with other evidence. This is how beginners become reliable analysts.

$Know when the tool is the right choice (and when it is not).
$Run a safe baseline command in a lab or authorized environment.
$Interpret the output in context instead of treating it as truth by itself.
$Correlate with other evidence sources (logs, packets, assets, owner context).
$Document findings and next actions so another analyst can reproduce your work.

preflight-checklist-before-using-tool

$Confirm authorization, target scope, and acceptable impact before running commands.
$Define the question first (troubleshooting, validation, hunting, triage, remediation proof).
$Identify the evidence source you will use to confirm or challenge tool output.
$Record time, host, interface/segment, and command used so results are reproducible.
$Decide what 'normal' should look like before testing edge cases or suspicious behavior.

how-experts-read-output

$Field recognition: Which fields actually matter for the question you asked?
$Scope validation: Does this output represent the host/segment/time window you intended?
$Confidence check: Is this direct evidence, inference, or a heuristic guess?
$Correlation step: Which second source should confirm this result (logs, PCAP, ticket, CMDB, host telemetry)?
$Decision step: What action should follow (close, escalate, tune, scan deeper, validate manually)?

official-links

open docs Official Greenbone Community Edition documentation user guide Greenbone documentation versions and guides community / project Greenbone project documentation portal

ethical-use-and-defense-scope

Run vulnerability scans only on systems you own or are authorized to assess. Scanners can generate load, trigger alerts, and sometimes disrupt unstable services if not scheduled and scoped properly.

Use scanning to support remediation and risk reduction, not to create fear-driven ticket volume. Good vulnerability management is collaborative and context-aware, especially in mixed production and legacy environments.

Protect scan credentials and results. Credentialed scans provide deep visibility into host software and configuration, which is powerful for defense but sensitive if mishandled.

tool-history-origin-and-purpose

$When created: OpenVAS emerged in 2006 after the Nessus licensing change in 2005; Greenbone later expanded it into a broader vulnerability management stack (now Greenbone Community Edition umbrella since 2022 naming).
$Why it was created: Defenders needed a free/open vulnerability scanning and management path for recurring assessments, remediation planning, and validation without depending only on proprietary tooling.

OpenVAS was created as an open-source continuation of vulnerability scanning after Nessus moved away from open-source licensing. Greenbone and contributors developed it further into a broader vulnerability management ecosystem.

why-defenders-still-use-it

People use OpenVAS / Greenbone CE because it supports recurring vulnerability management workflows, including authenticated and unauthenticated scanning, prioritization, and remediation follow-up for diverse environments.

How the tool evolved

+Started as a scanner-focused open-source fork and matured into a broader vulnerability management framework (GVM / Greenbone ecosystem).
+Greenbone expanded surrounding components for feeds, management, and reporting workflows.
+The Greenbone Community Edition naming helps distinguish open-source/community components and releases.

when-this-tool-is-a-good-fit

+Recurring vulnerability scanning for internal and external assets.
+Credentialed scan workflows to improve remediation accuracy.
+Validation of patching and configuration hardening changes.
+Evidence-based vulnerability triage and owner assignment.

when-to-use-another-tool-or-source

!When you need host process/user context, pair with endpoint or OS logs.
!When you need ownership and business impact, pair with CMDB/ticketing/asset context.
!When the tool output is ambiguous, validate using a second evidence source before concluding.
!When production risk is high, test in a lab first and use change coordination.

1. What Vulnerability Management Tools Actually Provide

OpenVAS / Greenbone CE helps defenders identify potential vulnerabilities, misconfigurations, and exposed services through recurring scans. It provides a structured way to move from “we should scan” to a repeatable vulnerability management process.

It is important to understand what scanners do and do not do. They surface likely issues and provide evidence and prioritization clues, but they do not replace architecture knowledge, business context, or validation of unusual findings.

For blue teams, the real value is operational rhythm: recurring assessment, triage, assignment, remediation, and validation. The tool is the platform; the process is the outcome.

2. Credentialed vs Unauthenticated Scans in Practice

Unauthenticated scans are valuable for exposure perspective: what can be observed from the network without logging into the host. They often catch externally visible services and protocol-level weaknesses but may lack accuracy for installed software versions.

Credentialed scans improve depth and accuracy by inspecting installed packages and local configuration. This makes them especially useful for server patching and remediation planning where banner-based inference is incomplete.

Defenders should not choose one forever; they should combine both modes intentionally. Unauthenticated scans provide exposure insight, while credentialed scans support maintenance and validation depth.

3. Operationalizing a Vulnerability Program

A scanner becomes a program only when findings are triaged, assigned, and tracked to resolution. Define ownership, severity handling, exception workflows, and validation requirements before scan frequency becomes high.

Group findings by asset criticality, exposure, and service role. This makes remediation conversations more effective than delivering raw lists sorted only by scanner severity. Context is what turns scan output into risk reduction.

Establish recurring review cadences. Security teams and system owners should review new findings, overdue items, exceptions, and re-opened findings together to prevent backlog drift.

4. Triage, Validation, and False Positives

Scanners can produce false positives or ambiguous findings, especially in complex proxy, container, or custom-build environments. Build a validation step before escalating high-impact remediation requests.

Validation can include package checks, service banners, system configuration review, manual connection tests, or vendor advisories. The goal is not to challenge the scanner arbitrarily, but to make sure the remediation request is accurate and actionable.

Document validated false positives and revisit them periodically. Environment changes can cause previously false findings to become true later, and vice versa.

5. Scheduling, Scope, and Safety

Scan safety depends on scope and timing. Sensitive systems, production databases, and legacy infrastructure may require tailored schedules, reduced intensity, or coordination with owners. Do not assume every target tolerates the same scanning pattern.

Use scanning windows and communication plans so operational teams are aware of expected traffic. This reduces confusion with incident response teams and prevents routine scans from becoming avoidable escalations.

Build scan profiles that match environment classes (internet-facing servers, internal servers, workstations, test systems). Reusing documented profiles improves consistency and reduces accidental over-scanning.

6. Integrating Results With Remediation and Reporting

A good vulnerability management workflow integrates scanner findings with ticketing, ownership data, and remediation SLAs. The scanner should feed a process, not become the final destination for unresolved findings.

Reporting should focus on progress and risk reduction, not just counts. Useful metrics include time to triage, time to remediation by risk tier, overdue findings on critical assets, and repeat findings after supposed remediation.

Greenbone/OpenVAS is particularly useful as a learning platform for understanding these operational mechanics because it makes scan and finding workflows visible while still allowing teams to build their own prioritization logic.

7. Learning the Tool Ethically and Effectively

Start with a lab and a small set of hosts you control. Compare unauthenticated and credentialed results, validate a few findings manually, and practice writing remediation notes with evidence.

Focus on understanding why a finding appears, what evidence supports it, and what would count as remediation validation. This builds stronger vulnerability operations skills than simply exporting reports.

As you mature, add asset criticality tags, exception handling, and verification steps. The goal is to build a professional defensive workflow, not just scan more frequently.

scenario-teaching-playbooks

Use these scenario patterns to practice choosing the tool appropriately. The point is not just running commands; it is learning when and why the tool helps in a real defensive workflow.

1. Recurring vulnerability scanning for internal and external assets.

Suggested starting block: Service Status And Lab Prep

$Define the question you are trying to answer and the scope you are allowed to inspect.
$Collect baseline evidence using the selected command block.
$Interpret the result using known-good behavior and environment context.
$Correlate with another source (host logs, SIEM, tickets, inventory, or packet data).
$Record findings, confidence level, and the next defensive action.

2. Credentialed scan workflows to improve remediation accuracy.

Suggested starting block: Credentialed Validation (Post-Scan)

$Define the question you are trying to answer and the scope you are allowed to inspect.
$Collect baseline evidence using the selected command block.
$Interpret the result using known-good behavior and environment context.
$Correlate with another source (host logs, SIEM, tickets, inventory, or packet data).
$Record findings, confidence level, and the next defensive action.

3. Validation of patching and configuration hardening changes.

Suggested starting block: Remediation Tracking Workspace

$Define the question you are trying to answer and the scope you are allowed to inspect.
$Collect baseline evidence using the selected command block.
$Interpret the result using known-good behavior and environment context.
$Correlate with another source (host logs, SIEM, tickets, inventory, or packet data).
$Record findings, confidence level, and the next defensive action.

4. Evidence-based vulnerability triage and owner assignment.

Suggested starting block: Service Status And Lab Prep

$Define the question you are trying to answer and the scope you are allowed to inspect.
$Collect baseline evidence using the selected command block.
$Interpret the result using known-good behavior and environment context.
$Correlate with another source (host logs, SIEM, tickets, inventory, or packet data).
$Record findings, confidence level, and the next defensive action.

cli-workflows

Practical defensive workflows and lab-safe commands. Validate in a sandbox or authorized environment before using them in production.

cli-walkthroughs-with-expected-output

Start with one representative command from each workflow block. Read the sample output and explanation so you know what to look for when you run it yourself.

Service Status And Lab Prep

Beginner

Command

sudo systemctl status ospd-openvas || true

Example Output

● gvmd.service - Greenbone Vulnerability Manager daemon
   Active: active (running)

$ how to read it: Check for expected fields first, then validate whether the output actually answers your question. If not, refine scope or collect a second evidence source before concluding.

Credentialed Validation (Post-Scan)

Intermediate

Command

ssh admin@target "uname -a"

Example Output

# review output for expected fields, errors, and warnings
# compare against a known-good baseline in your environment

$ how to read it: Check for expected fields first, then validate whether the output actually answers your question. If not, refine scope or collect a second evidence source before concluding.

Remediation Tracking Workspace

Advanced

Command

mkdir -p vuln-ops/{exports,validation,notes}

Example Output

# review output for expected fields, errors, and warnings
# compare against a known-good baseline in your environment

$ how to read it: Check for expected fields first, then validate whether the output actually answers your question. If not, refine scope or collect a second evidence source before concluding.

command-anatomy-and-expert-usage

This breaks down each command so learners understand intent, risk, and interpretation. Expert use is not about memorizing syntax; it is about selecting the right command for the right question and reading the result correctly.

Service Status And Lab Prep

Beginner

Command

sudo systemctl status ospd-openvas || true

Command Anatomy

$Base command: sudo
$Primary arguments/options: systemctl status ospd-openvas || true
$Operator goal: run this command only when it answers a clear defensive question.

Use And Risk

$ intent: Service health verification for a required component.

$ risk: Medium-High: may affect services/platform state depending on command and environment.

$ learning focus: Baseline command: learn what normal output looks like.

Show sample output and interpretation notes

● gvmd.service - Greenbone Vulnerability Manager daemon
   Active: active (running)

$ expert reading pattern: Confirm the output matches your intended scope, identify the key fields, then validate with a second source before making decisions.

Service Status And Lab Prep

Beginner

Command

sudo systemctl status gvmd || true

Command Anatomy

$Base command: sudo
$Primary arguments/options: systemctl status gvmd || true
$Operator goal: run this command only when it answers a clear defensive question.

Use And Risk

$ intent: Service health verification for a required component.

$ risk: Medium-High: may affect services/platform state depending on command and environment.

$ learning focus: Intermediate step: refine scope or extract more useful evidence.

Show sample output and interpretation notes

● gvmd.service - Greenbone Vulnerability Manager daemon
   Active: active (running)

$ expert reading pattern: Confirm the output matches your intended scope, identify the key fields, then validate with a second source before making decisions.

Service Status And Lab Prep

Beginner

Command

sudo systemctl status gsad || true

Command Anatomy

$Base command: sudo
$Primary arguments/options: systemctl status gsad || true
$Operator goal: run this command only when it answers a clear defensive question.

Use And Risk

$ intent: Service health verification for a required component.

$ risk: Medium-High: may affect services/platform state depending on command and environment.

$ learning focus: Intermediate step: refine scope or extract more useful evidence.

Show sample output and interpretation notes

● gvmd.service - Greenbone Vulnerability Manager daemon
   Active: active (running)

$ expert reading pattern: Confirm the output matches your intended scope, identify the key fields, then validate with a second source before making decisions.

Service Status And Lab Prep

Beginner

Command

ss -tulpn | grep -E "9392|9390" || true

Command Anatomy

$Base command: ss
$Primary arguments/options: -tulpn | grep -E "9392|9390"
$Operator goal: run this command only when it answers a clear defensive question.

Use And Risk

$ intent: Quick evidence extraction from logs or command output.

$ risk: Review command impact before running; validate in lab first if uncertain.

$ learning focus: Advanced step: use after baseline and validation are understood.

Show sample output and interpretation notes

# review output for expected fields, errors, and warnings
# compare against a known-good baseline in your environment

$ expert reading pattern: Confirm the output matches your intended scope, identify the key fields, then validate with a second source before making decisions.

Credentialed Validation (Post-Scan)

Intermediate

Command

ssh admin@target "uname -a"

Command Anatomy

$Base command: ssh
$Primary arguments/options: admin@target "uname -a"
$Operator goal: run this command only when it answers a clear defensive question.

Use And Risk

$ intent: Collect, validate, or document evidence in a defensive workflow.

$ risk: Review command impact before running; validate in lab first if uncertain.

$ learning focus: Baseline command: learn what normal output looks like.

Show sample output and interpretation notes

# review output for expected fields, errors, and warnings
# compare against a known-good baseline in your environment

$ expert reading pattern: Confirm the output matches your intended scope, identify the key fields, then validate with a second source before making decisions.

Credentialed Validation (Post-Scan)

Intermediate

Command

ssh admin@target "cat /etc/os-release"

Command Anatomy

$Base command: ssh
$Primary arguments/options: admin@target "cat /etc/os-release"
$Operator goal: run this command only when it answers a clear defensive question.

Use And Risk

$ intent: Collect, validate, or document evidence in a defensive workflow.

$ risk: Review command impact before running; validate in lab first if uncertain.

$ learning focus: Intermediate step: refine scope or extract more useful evidence.

Show sample output and interpretation notes

# review output for expected fields, errors, and warnings
# compare against a known-good baseline in your environment

$ expert reading pattern: Confirm the output matches your intended scope, identify the key fields, then validate with a second source before making decisions.

Credentialed Validation (Post-Scan)

Intermediate

Command

ssh admin@target "dpkg -l | grep -i openssl"   # Debian/Ubuntu example

Command Anatomy

$Base command: ssh
$Primary arguments/options: admin@target "dpkg -l | grep
$Operator goal: run this command only when it answers a clear defensive question.

Use And Risk

$ intent: Quick evidence extraction from logs or command output.

$ risk: Review command impact before running; validate in lab first if uncertain.

$ learning focus: Intermediate step: refine scope or extract more useful evidence.

Show sample output and interpretation notes

# review output for expected fields, errors, and warnings
# compare against a known-good baseline in your environment

$ expert reading pattern: Confirm the output matches your intended scope, identify the key fields, then validate with a second source before making decisions.

Credentialed Validation (Post-Scan)

Intermediate

Command

ssh admin@target "rpm -qa | grep -i openssl"   # RHEL-family example

Command Anatomy

$Base command: ssh
$Primary arguments/options: admin@target "rpm -qa | grep
$Operator goal: run this command only when it answers a clear defensive question.

Use And Risk

$ intent: Quick evidence extraction from logs or command output.

$ risk: Review command impact before running; validate in lab first if uncertain.

$ learning focus: Advanced step: use after baseline and validation are understood.

Show sample output and interpretation notes

# review output for expected fields, errors, and warnings
# compare against a known-good baseline in your environment

$ expert reading pattern: Confirm the output matches your intended scope, identify the key fields, then validate with a second source before making decisions.

Remediation Tracking Workspace

Advanced

Command

mkdir -p vuln-ops/{exports,validation,notes}

Command Anatomy

$Base command: mkdir
$Primary arguments/options: -p vuln-ops/{exports,validation,notes}
$Operator goal: run this command only when it answers a clear defensive question.

Use And Risk

$ intent: Collect, validate, or document evidence in a defensive workflow.

$ risk: Review command impact before running; validate in lab first if uncertain.

$ learning focus: Baseline command: learn what normal output looks like.

Show sample output and interpretation notes

# review output for expected fields, errors, and warnings
# compare against a known-good baseline in your environment

$ expert reading pattern: Confirm the output matches your intended scope, identify the key fields, then validate with a second source before making decisions.

Remediation Tracking Workspace

Advanced

Command

printf "asset,finding,severity,owner,status,due
" > vuln-ops/tracker.csv

Command Anatomy

$Base command: printf
$Primary arguments/options: "asset,finding,severity,owner,status,due " > vuln-ops/tracker.csv
$Operator goal: run this command only when it answers a clear defensive question.

Use And Risk

$ intent: Collect, validate, or document evidence in a defensive workflow.

$ risk: Review command impact before running; validate in lab first if uncertain.

$ learning focus: Intermediate step: refine scope or extract more useful evidence.

Show sample output and interpretation notes

# review output for expected fields, errors, and warnings
# compare against a known-good baseline in your environment

$ expert reading pattern: Confirm the output matches your intended scope, identify the key fields, then validate with a second source before making decisions.

Remediation Tracking Workspace

Advanced

Command

column -s, -t vuln-ops/tracker.csv

Command Anatomy

$Base command: column
$Primary arguments/options: -s, -t vuln-ops/tracker.csv
$Operator goal: run this command only when it answers a clear defensive question.

Use And Risk

$ intent: Collect, validate, or document evidence in a defensive workflow.

$ risk: Review command impact before running; validate in lab first if uncertain.

$ learning focus: Advanced step: use after baseline and validation are understood.

Show sample output and interpretation notes

# review output for expected fields, errors, and warnings
# compare against a known-good baseline in your environment

$ expert reading pattern: Confirm the output matches your intended scope, identify the key fields, then validate with a second source before making decisions.

Service Status And Lab Prep

sudo systemctl status ospd-openvas || true
sudo systemctl status gvmd || true
sudo systemctl status gsad || true
ss -tulpn | grep -E "9392|9390" || true

Credentialed Validation (Post-Scan)

ssh admin@target "uname -a"
ssh admin@target "cat /etc/os-release"
ssh admin@target "dpkg -l | grep -i openssl"   # Debian/Ubuntu example
ssh admin@target "rpm -qa | grep -i openssl"   # RHEL-family example

Remediation Tracking Workspace

mkdir -p vuln-ops/{exports,validation,notes}
printf "asset,finding,severity,owner,status,due
" > vuln-ops/tracker.csv
column -s, -t vuln-ops/tracker.csv

defensive-use-cases

$Recurring vulnerability scanning for internal and external assets.
$Credentialed scan workflows to improve remediation accuracy.
$Validation of patching and configuration hardening changes.
$Evidence-based vulnerability triage and owner assignment.

common-mistakes

$Treating scanner severity as the only prioritization input.
$Running scans without owner coordination or safe scheduling.
$Skipping validation for high-impact findings and eroding trust with operations teams.
$Collecting results without a consistent ticketing and SLA process.

expert-habits-for-free-self-study

This site is a free teaching resource. Use this loop to train yourself like a working defender: ask a question, collect evidence, interpret carefully, validate, document, and repeat.

$Start with the least invasive command that can answer your question.
$Write down why you ran the command before interpreting the output.
$Treat output as evidence, not truth, until validated against another source.
$Save exact commands used so another analyst can reproduce your findings.
$Capture 'normal' examples during calm periods for future comparison.
$Escalate only after you can explain what you observed and why it matters.

knowledge-check

?What question is this tool best suited to answer first?
?What permissions or scope approvals are needed before using it?
?Which second evidence source should you pair with it for higher confidence?
?What does normal output look like for your environment?

teaching-answer-guide

Show teaching hints

#Start from the tool’s role and the scenario you are investigating.
#Never rely on one tool alone for high-confidence incident decisions.
#Document normal output patterns during calm periods so anomalies are easier to spot.
#Prefer lab validation for new commands, rules, or scans before production use.

practice-plan

# Run unauthenticated and credentialed scans in a lab and compare outputs.
# Validate at least three findings manually and document evidence.
# Build a simple vulnerability triage tracker with ownership and due dates.
# Define remediation validation steps before marking findings closed.

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