Skip to content

Latest commit

 

History

History
101 lines (82 loc) · 8.89 KB

attack-surface.md

File metadata and controls

101 lines (82 loc) · 8.89 KB

Attack Surface Analysis for owncloud/core

Attack Surface: Authentication Bypass (Login & Session Management)

  • 1. Authentication Bypass (Login & Session Management)

    • Description: Circumventing ownCloud's core authentication mechanisms to gain unauthorized access to user accounts or the system.
    • Core Contribution: ownCloud's core implements the login process, session token generation, handling, and validation. It also provides the core framework for MFA and password reset enforcement.
    • Example: An attacker exploits a flaw in core's session token generation to predict a valid session ID, hijacking an active user's session. Or, a vulnerability in the core password reset flow logic allows an attacker to reset a user's password without proper authorization.
    • Impact: Complete account takeover, unauthorized access to all user data, potential for privilege escalation to administrator.
    • Risk Severity: Critical
    • Mitigation Strategies:
      • Developers:
        • Implement robust session management within core, using cryptographically secure random token generation.
        • Enforce strict session expiration and invalidation policies in core.
        • Thoroughly test and secure the core password reset flow, including token generation, and rate limiting.
        • Implement and enforce strong password complexity requirements in core.
        • Provide and enforce the core framework for Multi-Factor Authentication (MFA).
        • Regularly audit and review authentication-related code in core.
        • Use well-vetted authentication libraries and avoid custom implementations where possible within core.

Attack Surface: Unauthorized File Access (Sharing & Permissions)

  • 2. Unauthorized File Access (Sharing & Permissions)

    • Description: Accessing files or folders that a user should not have permission to access, due to flaws in ownCloud's core sharing or permissions model.
    • Core Contribution: ownCloud's core defines and enforces the sharing model (public links, user-to-user, group sharing), Access Control Lists (ACLs), and API authorization logic.
    • Example: An attacker exploits a bug in the core ACL enforcement logic to access a file shared with a different user, bypassing the intended permissions.
    • Impact: Data leakage, unauthorized access to sensitive files, potential for data modification or deletion.
    • Risk Severity: High
    • Mitigation Strategies:
      • Developers:
        • Thoroughly test and audit the core sharing and permissions logic, including edge cases and complex scenarios.
        • Implement robust input validation and sanitization within core to prevent injection attacks that could bypass permissions checks.
        • Regularly review and update the core ACL enforcement mechanisms.
        • Consider using a formal model for access control (e.g., RBAC, ABAC) within core to ensure consistency and reduce errors.

Attack Surface: WebDAV Exploitation

  • **3. WebDAV Exploitation

    • Description: Exploiting vulnerabilities in ownCloud's core implementation of the WebDAV protocol to gain unauthorized access, modify files, or cause a denial of service.
    • Core Contribution: ownCloud's core provides the WebDAV server functionality, handling all WebDAV requests and enforcing authentication/authorization within the WebDAV context.
    • Example: An attacker uses a specially crafted WebDAV PUT request handled by core to upload a malicious file that bypasses file type restrictions or overwrites a critical system file. Or, a vulnerability in the core PROPFIND handler allows an attacker to enumerate files and folders they shouldn't have access to.
    • Impact: Unauthorized file access, data modification, denial of service, potential for remote code execution (depending on the vulnerability).
    • Risk Severity: High
    • Mitigation Strategies:
      • Developers:
        • Thoroughly test and audit the core WebDAV implementation, including all supported methods (PUT, GET, PROPFIND, DELETE, etc.).
        • Implement robust input validation and sanitization for all WebDAV requests within core.
        • Enforce strict authentication and authorization within the core WebDAV context.
        • Regularly update any core WebDAV libraries and dependencies.

Attack Surface: OCS API Abuse

  • **4. OCS API Abuse

    • Description: Exploiting vulnerabilities in the core ownCloud Share API (OCS) to gain unauthorized access to data or perform unauthorized actions.
    • Core Contribution: The core provides the OCS API endpoints and handles authentication, authorization, and data exposure through the API.
    • Example: An attacker discovers a core API endpoint that leaks sensitive user information without proper authentication. Or, a flaw in a core API allows an attacker to create or modify shares without the necessary permissions.
    • Impact: Data leakage, unauthorized access to user data and shares, potential for privilege escalation.
    • Risk Severity: High
    • Mitigation Strategies:
      • Developers:
        • Thoroughly test and audit all core OCS API endpoints, including authentication, authorization, and input validation.
        • Implement robust rate limiting within core to prevent brute-force attacks on API endpoints.
        • Use API keys or other strong authentication mechanisms for API access enforced by core.
        • Regularly review and update the core API security controls.

Attack Surface: Server-Side Encryption Bypass (if core encryption is used)

  • **5. Server-Side Encryption Bypass (if core encryption is used)

    • Description: Circumventing ownCloud's server-side encryption if implemented in core to gain access to unencrypted data.
    • Core Contribution: If core implements server-side encryption at rest, it manages the key generation, encryption/decryption processes, and storage of encrypted data.
    • Example: An attacker exploits a vulnerability in the core key management system to obtain the encryption keys, allowing them to decrypt all stored data. Or, a flaw in the core encryption/decryption process allows an attacker to inject malicious code or bypass the encryption altogether.
    • Impact: Complete data breach, unauthorized access to all stored data in unencrypted form.
    • Risk Severity: Critical
    • Mitigation Strategies:
      • Developers:
        • Use strong, industry-standard encryption algorithms (e.g., AES-256) within core.
        • Implement robust key management practices within core, including secure key storage, rotation, and access control.
        • Thoroughly test and audit the core encryption/decryption processes.
        • Regularly review and update the core encryption implementation.

Attack Surface: Configuration File Vulnerabilities (config.php)

  • **6. Configuration File Vulnerabilities (config.php)

    • Description: Exploiting weaknesses in how ownCloud core handles the config.php file to gain unauthorized access or modify system settings.
    • Core Contribution: Core relies on config.php for crucial settings and handles its parsing and access.
    • Example: An attacker gains read access to config.php due to misconfigured file permissions (though this is server config, core's handling of the file is the issue), revealing database credentials and other sensitive information. Or, an attacker exploits a vulnerability to inject malicious code into config.php via a core flaw, altering the system's behavior.
    • Impact: Database compromise, system takeover, data leakage, denial of service.
    • Risk Severity: Critical
    • Mitigation Strategies: * Developers:
      • Ensure config.php is created with the most restrictive file permissions possible (server config, but core should provide guidance).
      • Sanitize and validate all data read from config.php within core.
      • Avoid storing sensitive credentials directly in config.php if possible (use environment variables or other secure storage mechanisms, and core should provide mechanisms for this).
      • Regularly review and update the core config.php handling code.