EUVD-2023-3214 Technical Analysis Report

CVE-2023-48910: Server-Side Request Forgery in Microcks

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1. VULNERABILITY ASSESSMENT AND SEVERITY EVALUATION

Severity Classification

CVSS 3.1 Base Score: 9.8 (CRITICAL)

Vector Analysis (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

• Attack Vector (AV:N): Network-exploitable, requiring no physical or local access
• Attack Complexity (AC:L): Low complexity; no specialized conditions required
• Privileges Required (PR:N): No authentication necessary
• User Interaction (UI:N): No user interaction required for exploitation
• Scope (S:U): Unchanged; impacts remain within vulnerable component
• Confidentiality Impact (C:H): High; potential for complete information disclosure
• Integrity Impact (I:H): High; possible data modification capabilities
• Availability Impact (A:H): High; potential for service disruption

Risk Assessment

This vulnerability represents a CRITICAL security risk due to:

• Unauthenticated remote exploitation capability
• Minimal technical skill required for exploitation
• Potential for complete system compromise
• Direct access to internal network resources
• Exposure of sensitive information and credentials

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2. POTENTIAL ATTACK VECTORS AND EXPLOITATION METHODS

Attack Surface

The vulnerability exists in two primary endpoints:

• /jobs - Job management interface
• /artifact/download - Artifact retrieval functionality

Exploitation Methodology

Primary Attack Vector: SSRF via Crafted GET Requests

Typical Exploitation Flow:
1. Attacker identifies exposed Microcks instance
2. Crafts malicious GET request to vulnerable endpoints
3. Embeds internal/external URLs in request parameters
4. Server processes request and fetches attacker-specified resources
5. Response data returned to attacker or triggers secondary actions

Exploitation Scenarios

Scenario 1: Internal Network Reconnaissance

GET /artifact/download?url=http://169.254.169.254/latest/meta-data/
GET /jobs?importUrl=http://internal-service:8080/admin

• Access cloud metadata services (AWS, Azure, GCP)
• Enumerate internal network services
• Identify internal infrastructure topology

Scenario 2: Credential Harvesting

GET /artifact/download?url=file:///etc/passwd
GET /jobs?importUrl=http://internal-credentials-store/api/keys

• Extract local system files
• Access internal credential stores
• Retrieve API keys and authentication tokens

Scenario 3: Port Scanning and Service Discovery

• Leverage timing differences to map internal networks
• Identify running services on internal hosts
• Bypass firewall restrictions using server as proxy

Scenario 4: Server-Side Code Execution (Chained Attack)

• Combine with other vulnerabilities
• Trigger deserialization attacks via fetched content
• Execute remote code through protocol handlers

Technical Exploitation Indicators

• Unusual outbound connections from Microcks server
• Requests to internal IP ranges (RFC 1918)
• Access attempts to cloud metadata endpoints
• Abnormal file:// or gopher:// protocol usage
• High volume of requests to /jobs or /artifact/download endpoints

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3. AFFECTED SYSTEMS AND SOFTWARE VERSIONS

Vulnerable Versions

Microcks versions ≤ 1.7.1 (all releases up to and including 1.7.1)

Deployment Contexts at Risk

Container Environments:

• Kubernetes deployments
• Docker containerized instances
• OpenShift platforms
• Cloud-native microservices architectures

Cloud Platforms:

• AWS ECS/EKS deployments
• Azure Container Instances/AKS
• Google Cloud Run/GKE
• Private cloud infrastructures

Enterprise Integration: Organizations using Microcks for:

• API mocking and testing
• Service virtualization
• Microservices development
• CI/CD pipeline integration
• Contract testing frameworks

Identification Methods

Version Detection:

# Check running container version
docker inspect <container_id> | grep -i version

# API version endpoint (if available)
curl http://<microcks-host>/api/version

# Kubernetes deployment check
kubectl get deployment microcks -o yaml | grep image:

Network Scanning:

# Identify exposed Microcks instances
nmap -p 8080,8443 -sV --script http-title <network_range>

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4. RECOMMENDED MITIGATION STRATEGIES

Immediate Actions (Priority 1 - Within 24 Hours)

1. Version Upgrade

• Upgrade to Microcks version 1.8.0 or later immediately
• Verify patch application through version confirmation
• Test functionality in staging environment before production deployment

2. Network Segmentation

Implement strict network controls:
- Restrict Microcks server outbound connections
- Whitelist only necessary external domains
- Block access to internal IP ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)
- Block cloud metadata endpoints (169.254.169.254)
- Disable unnecessary protocol handlers (file://, gopher://, ftp://)

3. Access Control Implementation

• Implement authentication for all Microcks endpoints
• Deploy Web Application Firewall (WAF) with SSRF rules
• Restrict access to /jobs and /artifact/download endpoints
• Implement IP whitelisting for administrative functions

Short-term Mitigations (Priority 2 - Within 1 Week)

4. Web Application Firewall Rules

WAF Rule Examples:
- Block requests with internal IP addresses in parameters
- Detect and block file:// protocol usage
- Rate limit requests to vulnerable endpoints
- Implement URL validation regex patterns
- Block requests to cloud metadata services

5. Monitoring and Detection

Implement logging for:
- All requests to /jobs and /artifact/download
- Outbound connection attempts from Microcks
- Failed authentication attempts
- Unusual parameter patterns in GET requests
- Access to internal IP ranges

6. Input Validation Enhancement If immediate patching is impossible:

Implement reverse proxy with URL validation:
- Whitelist allowed domains/protocols
- Validate and sanitize URL parameters
- Reject requests containing internal IP addresses
- Block non-HTTP/HTTPS protocols

Long-term Security Measures (Priority 3 - Ongoing)

7. Security Architecture Review

• Implement zero-trust network architecture
• Deploy service mesh with egress controls
• Implement least-privilege access principles
• Regular security assessments and penetration testing

8. Vulnerability Management Program

• Subscribe to Microcks security advisories
• Implement automated vulnerability scanning
• Establish patch management procedures
• Conduct regular security audits

9. Incident Response Preparation

Develop playbooks for:
- SSRF exploitation detection
- Compromised credential rotation
- Network isolation procedures
- Forensic data collection

Compensating Controls (If Patching Delayed)

Temporary Workaround Configuration:

# Example Kubernetes NetworkPolicy
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: microcks-egress-restriction
spec:
  podSelector:
    matchLabels:
      app: microcks
  policyTypes:
  - Egress
  egress:
  - to:
    - podSelector: {}
    ports:
    - protocol: TCP
      port: 443
  - to:
    - namespaceSelector: {}
    ports:
    - protocol: TCP
      port: 53

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5. IMPACT ON EUROPEAN CYBERSECURITY LANDSCAPE

Regulatory Compliance Implications

NIS2 Directive Considerations:

• Affects essential and important entities using Microcks
• Requires incident reporting within 24 hours of detection
• Mandates implementation of appropriate security measures
• Potential