Objective: Gain unauthorized access to sensitive data (messages, files, user information) and/or control over the Mattermost server, leading to data breaches, service disruption, or lateral movement within the network.
+-------------------------------------------------+
| Gain Unauthorized Access/Control of Mattermost |
+-------------------------------------------------+
|
+--------------------------------+--------------------------------+--------------------------------+
| | | |
+------+------+ +------+------+ +------+------+
| Exploit | | Exploit | | Exploit |
| Server-Side| | API | | Server-Side|
|Vulnerability| |Vulnerability| |Vulnerability|
+------+------+ +------+------+ +------+------+
| | |
|
+------+------+ +------+------+ +------+------+
| ***Code | |!!!Improper| |!!!RCE via |
| Injection***| | Auth/Authz| | crafted !!!|
| (e.g., | | on API !!!| | message |
| search) | | Endpoints | | format |
+------+------+ +------+------+ +------+------+
| |
+------+------+ +------+------+
|***Unvalida| | ***Data |
|ted Input***| | Leakage***|
| to Server | | via API |
+------+------+ +------+------+
Attack Tree Path: Exploit Server-Side Vulnerability (Code Injection Path)
* **Code Injection (e.g., search):**
* **Description:** An attacker crafts a malicious input (e.g., a search query) that, due to insufficient input validation and/or output encoding, is interpreted as code by the Mattermost server and executed. This could be JavaScript, SQL, or other code depending on the vulnerable component.
* **Likelihood:** Medium
* **Impact:** High (RCE, data breach)
* **Effort:** Medium
* **Skill Level:** Intermediate to Advanced
* **Detection Difficulty:** Medium
* **Mitigation:**
* Implement strict input validation using a whitelist approach (allow only known-good characters and patterns).
* Use parameterized queries or prepared statements for database interactions to prevent SQL injection.
* Employ output encoding to ensure that user-supplied data is treated as data, not code.
* Use a Web Application Firewall (WAF) with rules to detect and block common injection patterns.
* Regularly perform static code analysis and dynamic application security testing (DAST).
* **Unvalidated Input to Server:**
* **Description:** A broader category encompassing any server-side component that accepts user input without proper validation. This could be in message processing, file uploads, profile updates, or any other feature where user data is processed.
* **Likelihood:** Medium
* **Impact:** High (RCE, data modification, various other attacks depending on the context)
* **Effort:** Low to Medium
* **Skill Level:** Beginner to Intermediate
* **Detection Difficulty:** Medium
* **Mitigation:**
* Implement a strict "deny-by-default" input validation policy. Validate *all* input based on expected type, length, format, and range.
* Use a centralized input validation library or framework.
* Regularly review code for any instances of unvalidated input.
* Perform fuzz testing to identify unexpected input handling issues.
Attack Tree Path: Exploit API Vulnerability (Data Leakage Path)
* **Improper Auth/Authz on API Endpoints (Critical Node):**
* **Description:** API endpoints lack proper authentication (verifying user identity) or authorization (verifying user permissions). This allows attackers to access data or perform actions they shouldn't be able to.
* **Likelihood:** Medium
* **Impact:** Very High (Unauthorized data access/modification, complete account takeover)
* **Effort:** Low to Medium
* **Skill Level:** Beginner to Intermediate
* **Detection Difficulty:** Medium
* **Mitigation:**
* Implement strong authentication for *all* API endpoints, using industry-standard protocols like OAuth 2.0 or API keys.
* Enforce the principle of least privilege: users and applications should only have access to the resources they absolutely need.
* Implement robust authorization checks to ensure users can only access data and perform actions they are permitted to.
* Regularly audit API access logs and configurations.
* **Data Leakage via API:**
* **Description:** The API unintentionally exposes sensitive information, such as user details, internal system information, or other data that should not be publicly accessible. This can happen through error messages, verbose responses, or poorly designed API endpoints.
* **Likelihood:** Medium
* **Impact:** Medium to High (Depends on the leaked data; could lead to further attacks or privacy violations)
* **Effort:** Low
* **Skill Level:** Beginner
* **Detection Difficulty:** Medium
* **Mitigation:**
* Carefully review all API responses to ensure they only contain the *necessary* data.
* Avoid exposing internal implementation details or error messages that could reveal sensitive information.
* Implement rate limiting to prevent attackers from scraping large amounts of data.
* Use data masking or redaction techniques to protect sensitive fields.
* Regularly audit API responses for unintended data exposure.
Attack Tree Path: Exploit Server-Side Vulnerability (RCE Path)
* **RCE via crafted message format (Critical Node):**
* **Description:** The Mattermost server is vulnerable to Remote Code Execution (RCE) due to improper handling of specially crafted message formats. This could involve exploiting vulnerabilities in message parsing libraries, deserialization flaws, or other issues related to how messages are processed.
* **Likelihood:** Low
* **Impact:** Very High (Complete server compromise, potential for lateral movement within the network)
* **Effort:** High
* **Skill Level:** Advanced to Expert
* **Detection Difficulty:** Hard
* **Mitigation:**
* Fuzz test message parsing logic extensively with a wide variety of malformed inputs.
* Ensure robust error handling and avoid using unsafe deserialization methods.
* Keep all libraries and dependencies related to message processing up to date.
* Implement strict input validation on message content, even before it reaches parsing logic.
* Consider using a memory-safe language or runtime environment for critical message processing components.
* Regularly perform security audits and penetration testing focused on message handling.