Maven Dependency Audit Skill

Audit Maven dependencies for updates, vulnerabilities, and conflicts.

When to Use

• User says "check dependencies" / "audit dependencies" / "outdated dependencies"
• Before a release
• Regular maintenance (monthly recommended)
• After security advisory

Audit Workflow

1. Check for updates - Find outdated dependencies
2. Analyze tree - Find conflicts and duplicates
3. Security scan - Check for vulnerabilities
4. Report - Summary with prioritized actions

1. Check for Outdated Dependencies

Command

mvn versions:display-dependency-updates

Output Analysis

[INFO] The following dependencies in Dependencies have newer versions:
[INFO]   org.slf4j:slf4j-api ......................... 1.7.36 -> 2.0.9
[INFO]   com.fasterxml.jackson.core:jackson-databind . 2.14.0 -> 2.16.1
[INFO]   org.junit.jupiter:junit-jupiter ............. 5.9.0 -> 5.10.1

Categorize Updates

Check Plugin Updates Too

mvn versions:display-plugin-updates

2. Analyze Dependency Tree

Full Tree

mvn dependency:tree

Filter for Specific Dependency

mvn dependency:tree -Dincludes=org.slf4j

Find Conflicts

Look for:

[INFO] +- com.example:module-a:jar:1.0:compile
[INFO] |  \- org.slf4j:slf4j-api:jar:1.7.36:compile
[INFO] +- com.example:module-b:jar:1.0:compile
[INFO] |  \- org.slf4j:slf4j-api:jar:2.0.9:compile (omitted for conflict)

Flags:

• (omitted for conflict) - Version conflict resolved by Maven
• (omitted for duplicate) - Same version, no issue
• Multiple versions of same library - Potential runtime issues

Analyze Unused Dependencies

mvn dependency:analyze

Output:

[WARNING] Used undeclared dependencies found:
[WARNING]    org.slf4j:slf4j-api:jar:2.0.9:compile
[WARNING] Unused declared dependencies found:
[WARNING]    commons-io:commons-io:jar:2.11.0:compile

3. Security Vulnerability Scan

Option A: OWASP Dependency-Check (Recommended)

Add to pom.xml:

<plugin>
    <groupId>org.owasp</groupId>
    <artifactId>dependency-check-maven</artifactId>
    <version>9.0.7</version>
</plugin>

Run:

mvn dependency-check:check

Output: HTML report in target/dependency-check-report.html

Option B: Maven Dependency Plugin

mvn dependency:analyze-report

Option C: GitHub Dependabot

If using GitHub, enable Dependabot alerts in repository settings.

Severity Levels

4. Generate Audit Report

Output Format

## Dependency Audit Report

**Project:** {project-name}
**Date:** {date}
**Total Dependencies:** {count}

### Security Issues

| Dependency | Current | CVE | Severity | Fixed In |
|------------|---------|-----|----------|----------|
| log4j-core | 2.14.0 | CVE-2021-44228 | Critical | 2.17.1 |

### Outdated Dependencies

#### Major Updates (Review Required)
| Dependency | Current | Latest | Notes |
|------------|---------|--------|-------|
| slf4j-api | 1.7.36 | 2.0.9 | API changes, see migration guide |

#### Minor/Patch Updates (Safe)
| Dependency | Current | Latest |
|------------|---------|--------|
| junit-jupiter | 5.9.0 | 5.10.1 |
| jackson-databind | 2.14.0 | 2.16.1 |

### Conflicts Detected
- slf4j-api: 1.7.36 vs 2.0.9 (resolved to 2.0.9)

### Unused Dependencies
- commons-io:commons-io:2.11.0 (consider removing)

### Recommendations
1. **Immediate:** Update log4j-core to fix CVE-2021-44228
2. **This sprint:** Update minor/patch versions
3. **Plan:** Evaluate slf4j 2.x migration

Common Scenarios

Scenario: Check Before Release

# Quick check
mvn versions:display-dependency-updates -q

# Full audit
mvn versions:display-dependency-updates && \
mvn dependency:analyze && \
mvn dependency-check:check

Scenario: Find Why Dependency is Included

mvn dependency:tree -Dincludes=commons-logging

Scenario: Force Specific Version (Resolve Conflict)

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>2.0.9</version>
        </dependency>
    </dependencies>
</dependencyManagement>

Scenario: Exclude Transitive Dependency

<dependency>
    <groupId>com.example</groupId>
    <artifactId>some-library</artifactId>
    <version>1.0</version>
    <exclusions>
        <exclusion>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
        </exclusion>
    </exclusions>
</dependency>

Token Optimization

• Use -q (quiet) flag for less verbose output
• Filter with -Dincludes=groupId:artifactId when looking for specific deps
• Run commands separately and summarize findings
• Don't paste entire dependency tree - summarize conflicts

Quick Commands Reference

Update Strategies

Conservative (Recommended for Production)

1. Update patch versions freely
2. Update minor versions with basic testing
3. Major versions require migration plan

Aggressive (For Active Development)

# Update all to latest (use with caution!)
mvn versions:use-latest-releases
mvn versions:commit  # or versions:revert

Selective

# Update specific dependency
mvn versions:use-latest-versions -Dincludes=org.junit.jupiter