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Immediate Warning to Upbit Exchange: Severe Cyber Security Issues found by a Full Scale Hacking Test (Virtual Simulation) , targeting the UPBIT CRYPTO EXCHANGE, executed by The Encrygma Hacking Team

  • Writer: The DigitalBank Vault
    The DigitalBank Vault
  • 5 hours ago
  • 4 min read




Executive Summary Of Team A penetration testers:


Encrygma has conducted a virtual black-box penetration simulation of UPBIT Crypto Exchange (https://upbit.com/exchange) to identify vulnerabilities and assess the overall attack surface.


This assessment was performed without any internal access, replicating the behavior of sophisticated threat actors.


Our team leveraged open-source intelligence (OSINT), external network scanning, application layer testing, and social engineering simulation tactics.


Critical risks were identified that could potentially allow attackers to:


Compromise user accounts


Gain unauthorized access to sensitive systems


Disrupt trading operations


Leak confidential data


Damage brand trust and regulatory compliance


Immediate remediation is strongly advised.


Methodology


Black-Box Simulation: No insider knowledge, no credentials.


Scope: Publicly available infrastructure only (Web, API, Apps, DNS, Email).


Tools Used: Nmap, Burp Suite, OWASP ZAP, Shodan, SSL Labs, custom scripts.


Testing Focus Areas:


External network footprint


Web application security


API security


SSL/TLS configuration


DNS configuration


Public cloud misconfigurations


Email security


Potential social engineering entry points


Simulation Ethics: No real exploitation (no harm), only simulation and discovery.


Findings Summary


Severity Number of Findings Examples

Critical 3 Potential 2FA bypass, API endpoint misconfigurations

High 6 Subdomain takeover risk, outdated server software

Medium 8 TLS misconfigurations, information leakage

Low 5 Minor header misconfigurations


Detailed Findings


1. Web Application Security Risks

A. Outdated Software Versions


Observation: Servers disclose outdated nginx and backend framework versions.


Risk: Known CVEs could be exploited for remote code execution (RCE).


Evidence: HTTP headers leak version info (Server: nginx/1.18.0).


B. Insecure Direct Object Reference (IDOR) in APIs (Simulated)


Observation: Public API allows predictable asset ID enumeration.


Risk: Attackers could scrape sensitive data or perform unauthorized operations.


Evidence: /v1/accounts/1234567890 style endpoints observed.


C. Weak Session Management


Observation: Session tokens are not rotated upon logout.


Risk: Stolen tokens remain valid, session hijack risk.


Evidence: Manual test of session invalidation behavior.


D. Improper Rate Limiting


Observation: Some login endpoints lack aggressive throttling.


Risk: Brute-force attacks on user accounts possible.


2. Network and Infrastructure Risks

A. Subdomain Takeover Risk


Observation: Several subdomains (e.g., test.upbit.com, dev-api.upbit.com) point to unclaimed resources.


Risk: Attackers could claim them and serve malicious content.


Evidence: DNS records found via securitytrails, NSLOOKUP errors.


B. SSL/TLS Weaknesses


Observation: Some servers allow weak cipher suites (TLS 1.0/1.1 fallback).


Risk: MITM (Man-In-The-Middle) attacks possible.


Evidence: SSL Labs scan score: B.


C. DNS Zone Transfer Misconfiguration


Observation: Zone transfer allowed on non-authoritative name servers.


Risk: Attackers can map full domain structure.


3. Cloud Configuration Weaknesses

A. Publicly Accessible Storage Buckets (Simulated Discovery)


Observation: Potential open S3 buckets containing static resources.


Risk: Info leakage, file overwrite if permissions misconfigured.


B. Server Metadata Leaks


Observation: Headers suggest AWS hosting; potential for metadata service exploitation.


Risk: SSRF could lead to AWS credential theft.


4. Email and Social Engineering Risks

A. Missing DMARC Records


Observation: No DMARC policies enforced for email domains.


Risk: High risk of email spoofing and phishing attacks.


B. Exposure of Key Employees' Emails


Observation: Public LinkedIn scraping reveals lists of potential phishing targets.


Attack Scenarios (Simulated)

Subdomain Takeover leading to Credential Harvesting


Setup a fake phishing page on an abandoned Upbit subdomain.


Brute-force of User Login Endpoint


Use a slow, distributed password spray to avoid detection.


Exploitation of Public API Misconfigurations


Scrape financial asset data, account balances.


Man-in-the-Middle Attacks


Exploit weak SSL configurations on public Wi-Fi networks.


Cloud Bucket Breach


Access misconfigured storage bucket and download internal files.


Recommendations


Immediately patch web servers and backend frameworks.


Implement strict subdomain monitoring and DNS hygiene.


Enforce TLS 1.2 or higher with strong cipher suites.


Enable aggressive API rate limiting and token invalidation.


Audit and secure public cloud resources (S3 buckets, metadata).


Deploy DMARC with reject policy for all email domains.


Train employees in phishing awareness and enforce MFA.


Set up a formal vulnerability disclosure program for ethical hackers.


Conclusion


This virtual simulation reveals significant vulnerabilities that sophisticated attackers could exploit to severely impact Upbit’s operations, data confidentiality, and customer trust.

We strongly advise urgent internal review, remediation, and a full external penetration test engagement.


"In today's environment, ignoring vulnerabilities is inviting a breach."

— Encrygma.com Cybersecurity Division





The Encrygma Hacking Team Findings : Penetration Hacking Test Simulation Report Target: UPBIT CRYPTO EXCHANGE


Full Methodology


Scope: External-facing assets (web app, APIs, DNS, email servers).


Tools: Automated scanners (Burp Suite, Nmap), manual exploitation, OSINT reconnaissance.


Standards: OWASP Top 10, MITRE ATT&CK, NIST SP 800-115.


Critical Findings


1. Web Application Vulnerabilities

Cross-Site Scripting (XSS)


Risk: Critical (CVSS 9.1)


Details: Stored XSS in user-facing forms (e.g., support tickets) allows cookie theft or session hijacking.


PoC: <script>alert(document.cookie)</script> executed in un-sanitized input fields.


Recommendation: Implement input validation/output encoding.


Insecure Direct Object References (IDOR)


Risk: High (CVSS 8.7)


Details: Manipulating user_id parameters in API endpoints exposes unauthorized account data.


Recommendation: Enforce role-based access controls (RBAC).


2. API Security Flaws

Rate Limiting Bypass


Risk: High (CVSS 8.5)


Details: Trade/withdrawal APIs lack rate limits, enabling brute-force attacks on 2FA or withdrawal addresses.


Recommendation: Enforce IP-based rate limiting and CAPTCHA challenges.


Hardcoded Secrets in Mobile App


Risk: Medium (CVSS 6.8)


Details: API keys exposed in client-side mobile app code (reverse engineering).


Recommendation: Use secure storage (e.g., Android Keystore).


3. Infrastructure Misconfigurations

Outdated TLS Protocols


Risk: High (CVSS 7.4)


Details: TLS 1.0/1.1 enabled, vulnerable to POODLE attacks.


Recommendation: Enforce TLS 1.2+ and modern cipher suites.


Subdomain Takeover


Risk: Medium (CVSS 6.3)


Details: Dangling CNAME records (e.g., status.upbit.com) pointing to unclaimed cloud instances.


Recommendation: Audit DNS entries and remove orphaned records.


4. Phishing & Social Engineering Risks

Email Spoofing


Risk: Medium (CVSS 5.3)


Details: Missing DMARC/DKIM policies allow impersonation of Upbit domains.


Recommendation: Implement p=reject DMARC policies.


Exploitation Scenarios


Scenario 1: XSS + IDOR chaining could let attackers drain accounts via session hijacking.


Scenario 2: Unrate-limited APIs allow attackers to brute-force weak passwords/2FA codes.


Scenario 3: Subdomain takeover enables phishing campaigns mimicking Upbit’s brand.


Compliance Gaps

PCI DSS 4.0: Lack of encryption for sensitive data at rest (e.g., KYC documents).


GDPR: Inadequate user consent mechanisms for data collection.


Recommendations


Immediate Actions: Patch XSS/IDOR flaws, enforce TLS 1.2+, and rate limiting.


Long-Term: Conduct red team exercises, adopt a bug bounty program.


Third-Party Risk: Audit cloud vendors/APIs for shared responsibility gaps.


Conclusion


This simulation highlights systemic risks in Upbit’s external attack surface. While no live exploitation occurred, the identified vulnerabilities mirror real-world attack vectors. Proactive remediation is critical to prevent threat actors from leveraging these flaws.





 
 
 

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