Objective: To gain unauthorized access to secrets (passwords, API keys, etc.) stored within a Vaultwarden instance, or to disrupt the service's availability for legitimate users.
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| Gain Unauthorized Access to Secrets/Disrupt Service |
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+--------------------------------+--------------------------------+--------------------------------+
| | |
+--------+--------+ +--------+--------+ +--------+--------+ | Exploit | | Compromise | | Exploit | | Vaultwarden | | Admin | | Configuration | | Vulnerabilities| | Interface | | Errors | +--------+--------+ +--------+--------+ +--------+--------+ | | | +--------+--------+ +--------+--------+ +--------+--------+ | 1. RCE via | | A. Brute-Force | | ii. Exposed | | Attachment | | Admin | | Admin | | Handling | [CRITICAL] | Password | [HIGH RISK] | Token | [CRITICAL] +----------------+ +----------------+ +----------------+ | 5. SQLi via | | C. Credential | | Admin Panel | | Stuffing | [HIGH RISK] | (if | +----------------+ | vulnerable) | [CRITICAL] | D. Phishing | +----------------+ | Admin | [HIGH RISK] | 7. Bypass 2FA | +----------------+ | (if | | vulnerable) | [CRITICAL] +----------------+ +--------------------------------+ | +--------+--------+ | Abuse | | Vaultwarden | | Features | +--------+--------+ | +--------+--------+ | 3. DoS via | | Resource | | Exhaustion | [HIGH RISK] +----------------+
Attack Tree Path: 1. Exploit Vaultwarden Vulnerabilities
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1. RCE via Attachment Handling [CRITICAL]
- Description: An attacker uploads a malicious file that exploits a vulnerability in the server-side processing of attachments (e.g., image resizing, file type validation) to execute arbitrary code.
- Likelihood: Low
- Impact: Very High (Complete server takeover)
- Effort: High
- Skill Level: Advanced
- Detection Difficulty: Hard
- Mitigation:
- Strict file type validation before any processing (using magic numbers, not just extensions).
- Sandboxed library for file manipulation.
- Consider a separate, isolated service for attachment handling.
- Regularly audit and update dependencies related to file handling.
- Disable attachments if not strictly required.
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5. SQLi via Admin Panel (if vulnerable) [CRITICAL]
- Description: If the admin panel has any SQL injection vulnerabilities, an attacker could gain full control of the database.
- Likelihood: Low
- Impact: Very High (Full database compromise)
- Effort: High
- Skill Level: Advanced
- Detection Difficulty: Medium
- Mitigation:
- Use parameterized queries or an ORM.
- Avoid string concatenation for SQL queries.
- Regularly audit database interactions.
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7. Bypass 2FA (if vulnerable) [CRITICAL]
- Description: Flaws in the 2FA implementation allow an attacker to bypass this security measure.
- Likelihood: Low
- Impact: High (Bypassing 2FA significantly reduces security)
- Effort: High
- Skill Level: Advanced
- Detection Difficulty: Hard
- Mitigation:
- Thoroughly test the 2FA implementation, including edge cases.
- Ensure 2FA cannot be bypassed by manipulating requests or exploiting race conditions.
Attack Tree Path: 2. Compromise Admin Interface
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A. Brute-Force Admin Password [HIGH RISK]
- Description: A weak or easily guessable admin password is compromised through brute-force or dictionary attacks.
- Likelihood: Medium
- Impact: Very High (Full administrative access)
- Effort: Low
- Skill Level: Novice
- Detection Difficulty: Medium
- Mitigation:
- Enforce strong password policies (length, complexity, disallow common passwords).
- Account lockout after failed login attempts.
- Require Multi-Factor Authentication (MFA).
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C. Credential Stuffing [HIGH RISK]
- Description: An admin reuses their password, and a breach on another service allows attackers to use those credentials on Vaultwarden.
- Likelihood: Medium
- Impact: High (Full administrative access)
- Effort: Low
- Skill Level: Novice
- Detection Difficulty: Medium
- Mitigation:
- Educate admins about password reuse risks.
- Encourage password managers.
- Monitor for logins from unusual locations/IPs.
- Require Multi-Factor Authentication (MFA).
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D. Phishing Admin [HIGH RISK]
- Description: An attacker sends a phishing email, tricking the admin into entering credentials on a fake login page.
- Likelihood: High
- Impact: Very High (Full administrative access)
- Effort: Medium
- Skill Level: Intermediate
- Detection Difficulty: Hard
- Mitigation:
- Train admins to recognize phishing attacks.
- Implement email security measures (SPF, DKIM, DMARC).
- Require Multi-Factor Authentication (MFA).
Attack Tree Path: 3. Exploit Configuration Errors
- ii. Exposed Admin Token [CRITICAL]
- Description: The admin token is accidentally exposed (e.g., in logs, a public Git repo, environment variables).
- Likelihood: Low
- Impact: Very High (Immediate, full administrative access)
- Effort: Very Low
- Skill Level: Script Kiddie
- Detection Difficulty: Easy
- Mitigation:
- Protect the admin token as a highly sensitive secret.
- Store it securely (e.g., in a secrets management system).
- Rotate the token regularly.
- Never commit the token to version control.
Attack Tree Path: 4. Abuse Vaultwarden Features
- 3. DoS via Resource Exhaustion [HIGH RISK]
* Description: An attacker sends many requests, large attachments, or crafted requests to consume excessive server resources (CPU, memory, disk, database connections), causing a denial-of-service.
* Likelihood: Medium
* Impact: Medium (Disrupts service availability)
* Effort: Low
* Skill Level: Novice
* Detection Difficulty: Medium
* Mitigation:
- Implement rate limiting on API endpoints and user actions.
- Set reasonable limits on attachment sizes.
- Monitor server resource usage and set up alerts.
- Use a robust database connection pool.
- Consider a Web Application Firewall (WAF) for DDoS mitigation.