CVE-2025-55471: Youlai-boot Information Disclosure Flaw

CVE-2025-55471 Overview

CVE-2025-55471 is an Incorrect Access Control vulnerability affecting the getUserFormData function in youlai-boot v2.21.1. This security flaw allows unauthenticated attackers to access sensitive information belonging to other users through the network without requiring any user interaction.

The vulnerability stems from improper access control implementation (CWE-284) in the user data retrieval functionality, enabling unauthorized enumeration and extraction of user form data that should be protected by proper authorization checks.

Critical Impact

Attackers can exploit this vulnerability remotely to access sensitive user information without authentication, potentially leading to data breaches, privacy violations, and further targeted attacks against exposed users.

Affected Products

• youlai-boot v2.21.1
• youlai youlai-boot (cpe:2.3:a:youlai:youlai-boot:2.21.1)

Discovery Timeline

• 2025-11-26 - CVE-2025-55471 published to NVD
• 2025-12-05 - Last updated in NVD database

Technical Details for CVE-2025-55471

Vulnerability Analysis

The vulnerability exists in the getUserFormData function within youlai-boot, a Java-based backend framework. The function fails to properly validate whether the requesting user has authorization to access the requested user data, allowing any network-accessible attacker to retrieve sensitive form data for arbitrary users.

This represents a classic Broken Access Control flaw where the application correctly authenticates users but fails to enforce proper authorization boundaries when accessing resources. The function appears to accept user identifiers without verifying that the authenticated session has permission to view the specified user's data.

Root Cause

The root cause is an Improper Access Control vulnerability (CWE-284) in the getUserFormData function. The implementation lacks proper authorization checks to verify that the requesting entity has legitimate access rights to the user data being requested. This allows horizontal privilege escalation where any user (or unauthenticated attacker) can access data belonging to other users by manipulating request parameters.

Attack Vector

The attack is network-based and requires no authentication or user interaction. An attacker can exploit this vulnerability by:

1. Identifying the endpoint that handles getUserFormData requests
2. Crafting HTTP requests with manipulated user identifiers
3. Iterating through user IDs to enumerate and extract sensitive information
4. Collecting user form data that should be access-restricted

The exploitation is straightforward as it does not require any special privileges, making it highly accessible to attackers with basic reconnaissance skills. Technical details and proof-of-concept information are available in the GitHub Gist PoC.

Detection Methods for CVE-2025-55471

Indicators of Compromise

• Unusual patterns of API calls to the getUserFormData endpoint with sequential or enumerated user identifiers
• High volume of requests targeting user data endpoints from single IP addresses
• Access logs showing retrieval of multiple user records by unauthorized sessions
• Anomalous data export patterns indicating bulk user information harvesting

Detection Strategies

• Implement logging and alerting on the getUserFormData endpoint to detect enumeration attempts
• Monitor for requests accessing user data outside of normal application workflows
• Deploy web application firewall (WAF) rules to detect parameter manipulation on user identifier fields
• Review access logs for patterns of horizontal access violations across user accounts

Monitoring Recommendations

• Enable detailed audit logging for all user data access functions
• Set up alerts for failed authorization attempts or access to unauthorized resources
• Monitor API request patterns for signs of automated enumeration or scraping
• Implement rate limiting on sensitive user data endpoints to slow enumeration attacks

How to Mitigate CVE-2025-55471

Immediate Actions Required

• Upgrade youlai-boot beyond version 2.21.1 to a patched release when available
• Review and audit the getUserFormData function implementation for proper authorization checks
• Implement server-side access control validation to ensure users can only access their own data
• Apply network-level restrictions to limit access to sensitive API endpoints

Patch Information

Organizations should monitor the Gitee Issue Discussion for official patches and updates from the youlai-boot maintainers. The Gitee Project Repository should be checked for security releases addressing this vulnerability.

Workarounds

• Implement a custom authorization filter that validates user identity before processing getUserFormData requests
• Deploy a reverse proxy or WAF rule to restrict access to the affected endpoint
• Add application-level access control logic to verify the requesting user matches the requested user data
• Consider temporarily disabling the vulnerable endpoint until a proper fix is deployed

# Example WAF rule to restrict getUserFormData endpoint access
# Limit requests to authenticated sessions with matching user context
# This is a conceptual configuration - adapt to your WAF platform

# Rate limit the endpoint
location /api/getUserFormData {
    limit_req zone=userdata burst=5 nodelay;
    
    # Ensure authentication headers are present
    if ($http_authorization = "") {
        return 401;
    }
    
    proxy_pass http://backend;
}