Attack Surface: Cross-Site Scripting (XSS) - Stored XSS
- Description: Injection of malicious JavaScript into BookStack's stored content (pages, comments, descriptions), which executes when other users view that content.
- BookStack Contribution: BookStack's core function is content creation and editing, making it inherently vulnerable to stored XSS if input sanitization is flawed. The WYSIWYG editor and any free-text input fields are prime targets.
- Example: An attacker adds a page containing a malicious
<script>tag that steals cookies. When another user views the page, the script executes, sending their cookies to the attacker. - Impact: Account takeover, session hijacking, defacement, redirection to malicious sites, theft of sensitive information displayed on the page.
- Risk Severity: High
- Mitigation Strategies:
- Developer: Implement robust output encoding (context-sensitive escaping) for all user-supplied data. Use a well-vetted and actively maintained HTML sanitization library (e.g., DOMPurify, properly configured). Regularly review and update sanitization rules. Implement a strong Content Security Policy (CSP) to limit script execution.
- User: Keep BookStack updated.
Attack Surface: Authentication Bypass / Weak Authentication
- Description: Circumventing BookStack's authentication to gain unauthorized access.
- BookStack Contribution: BookStack's custom authentication logic (password management, session handling, social login/LDAP/SAML integrations) introduces potential vulnerabilities.
- Example: Exploiting a flaw in the password reset flow, using a weak/default password, or intercepting a poorly secured session cookie.
- Impact: Complete control over the compromised account, access to all content, potential for privilege escalation.
- Risk Severity: Critical
- Mitigation Strategies:
- Developer: Enforce strong password policies. Implement secure password reset (short-lived, cryptographically secure tokens). Use secure session management (HTTPS-only cookies, secure random IDs, proper expiration/invalidation). Thoroughly test/audit all authentication code, including integrations. Provide and encourage Multi-Factor Authentication (MFA).
- User: Use strong, unique passwords. Enable MFA. Log out when finished.
Attack Surface: Authorization Bypass (Privilege Escalation)
- Description: A user gaining access to content or functionality they shouldn't have.
- BookStack Contribution: BookStack's permission system is central to its operation. Flaws in this system are a direct vulnerability.
- Example: A "read-only" user modifying pages due to a bug in the permission checks.
- Impact: Unauthorized modification/deletion of content, access to sensitive information.
- Risk Severity: High
- Mitigation Strategies:
- Developer: Implement robust, centralized authorization checks before any action. Use a consistent permission model. Regularly audit authorization logic and conduct penetration testing. Follow the principle of least privilege.
- User: Report suspected permission issues.
Attack Surface: SQL Injection
- Description: Injecting malicious SQL into database queries.
- BookStack Contribution: While BookStack likely uses an ORM, custom SQL or improper input handling (especially in search or custom integrations) could lead to vulnerabilities.
- Example: An attacker injects SQL code into a search field to extract data.
- Impact: Complete database compromise, data theft/modification/deletion, potential server compromise.
- Risk Severity: Critical
- Mitigation Strategies:
- Developer: Use parameterized queries (prepared statements) for all database interactions. Avoid string concatenation for SQL. If using an ORM, ensure secure configuration and review custom SQL. Implement input validation.
- User: (No direct user mitigation).
Attack Surface: Unrestricted File Uploads
- Description: Uploading malicious files (e.g., web shells) executable on the server.
- BookStack Contribution: BookStack's file upload feature (for images, attachments) is a direct attack vector if not properly secured.
- Example: Uploading a PHP file containing a web shell, which is then executed.
- Impact: Server compromise, data theft/modification, denial of service.
- Risk Severity: Critical
- Mitigation Strategies:
- Developer: Implement strict file type validation (whitelist and content type verification). Limit file sizes. Store uploads outside the web root or with restricted execution permissions. Scan for malware. Rename uploaded files.
- User: (No direct user mitigation).