Exposing the Hidden Risks in Web Infrastructure

As enterprises increasingly rely on interconnected APIs and cloud-native architectures, even minor misconfigurations can evolve into critical security threats. A recent investigation by BeVigil, CloudSEK’s attack surface management platform, uncovered a severe unauthenticated Local File Inclusion (LFI) vulnerability affecting a subdomain associated with a major player in the travel industry. This blog explores the discovery and its ramifications, showcasing the urgent need for rigorous security hygiene in digital infrastructures.

The Discovery

BeVigil’s API Scanner identified a critical LFI vulnerability in one of the domain. The flaw allowed unauthenticated access to the server’s root-level file system through exposed readfile and loaddata endpoints. By chaining directory listing and file read functionalities, an attacker could gain comprehensive access to internal files, including source code, configuration data, and hardcoded credentials.

Key Findings

The affected web application implemented two endpoints—readfile?path= and loaddata?path=—which could be manipulated to list and access arbitrary files across the server. These endpoints lacked proper authentication and input validation.

• The readfile endpoint provided recursive directory listings, effectively exposing the internal architecture of the host server.
• The loaddata endpoint returned full content of any specified file, including sensitive resources such as /root/.ssh/authorized_keys and application configuration files.

Combining these endpoints enabled attackers to extract hardcoded credentials, source code, deployment scripts, and authentication secrets, thereby compromising the integrity and confidentiality of the infrastructure.

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Unmasking the Vulnerability: A Technical Breakdown

• ‍Unauthenticated Root-Level Access: Attackers could systematically browse the internal directory structure, identifying and extracting high-value assets. Also, exploiting the LFI requires no credentials, which exposes the entire server file system to remote attackers.

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• ‍Hardcoded Secrets and Configuration Files: Sensitive information such as database connection strings, API tokens, and internal service URLs were exposed in plain text. Source code and configuration files revealed internal APIs, logic flows, and service integrations, facilitating lateral movement across environments.

• Credential Harvesting: Retrieved credentials pose a high risk of privilege escalation and unauthorized access to production systems.

BeVigil’s Security Recommendations

BeVigil proposed a series of mitigation strategies to remediate the vulnerability and prevent similar issues:

• Immediate Deactivation of Vulnerable Endpoints: Remove or refactor dynamic file access features to eliminate arbitrary file read capabilities.
• Strict Input Validation: Sanitize and validate all user inputs to prevent directory traversal attacks and enforce path restrictions.
• Limit File System Permissions: Configure applications to run with the least privileges necessary, restricting access to critical directories.
• Disable Directory Listing: Turn off directory indexing on servers to prevent exposure of file structures.
• Credential Rotation and Revocation: Immediately rotate all exposed secrets and adopt a secure secret management system.
• Implement Logging and Monitoring: Enable robust logging and monitoring to detect unusual access patterns and respond to threats proactively.

Conclusion

This discovery underscores the severe implications of unauthenticated access vulnerabilities in publicly exposed web assets. By adopting a proactive security posture, enforcing least privilege principles, and integrating tools like BeVigil, organizations can fortify their digital ecosystems and safeguard critical assets from exploitation.