Subdomain Vulnerability in Vinnytsia Municipal Portal - Ukraine

Executive Summary

Dymo identified a subdomain misconfiguration vulnerability in the official Vinnytsia Municipal Portal in Ukraine. This flaw could allow malicious actors to host content under official-looking subdomains, facilitating sophisticated phishing campaigns and identity spoofing attacks.

Technical Analysis

Affected Infrastructure

• Organization: Vinnytsia Municipal Government
• Country: Ukraine
• Type: Subdomain Misconfiguration

Vulnerability Type

Subdomain Takeover / Wildcard DNS Misconfiguration

Technical Details

The vulnerability stems from:

1. Orphaned DNS Records: Pointing to deprovisioned services
2. Unclaimed Cloud Resources: S3/Azure/GCP buckets not properly secured
3. Wildcard DNS Abuse: Excessive wildcard routing allowing arbitrary subdomains
4. Certificate Gaps: No proper SSL/TLS validation on all subdomains

Attack Scenarios

Attackers can exploit this to:

• Phishing: Create support.vinnytsia-portal.gov.ua for credential theft
• Malware Distribution: Host malicious downloads on government domains
• Email Spoofing: Bypass DMARC with subdomain impersonation
• Brand Damage: Publish fake content under legitimate domains

Impact in Current Context

Given the ongoing conflict in Ukraine, this vulnerability poses heightened risks:

• Propaganda Distribution: Spread disinformation
• Targeted Attacks: Focus on government employees and citizens
• Trust Exploitation: Leverage government reputation for attacks
• Information Warfare: Compromise official communications

Responsible Disclosure

Reported to:

• Vinnytsia Municipal IT Department
• Ukrainian Cyber Police
• National Cybersecurity Coordination Center

Mitigation Recommendations

1. Audit all DNS records regularly
2. Remove orphaned subdomains
3. Implement strict wildcard DNS policies
4. Use certificate transparency monitoring
5. Enable HSTS preload for main domains

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This vulnerability was discovered through automated scanning by Dymo's security platform.