attack-tree.md

Attack Tree Analysis for elastic/elasticsearch-php

Objective: Compromise Application via Elasticsearch-PHP

Attack Tree Visualization

**Compromise Application via Elasticsearch-PHP** [CRITICAL NODE]
├───[AND] **Exploit Elasticsearch Query Injection** [CRITICAL NODE] [HIGH RISK PATH]
│   ├───[OR] **User-Controlled Search Parameters** [CRITICAL NODE]
│   ├───[AND] **Craft Malicious Elasticsearch Query** [CRITICAL NODE]
│   │   ├─── **Inject Malicious Operators/Functions** [CRITICAL NODE]
│   │   ├─── **Query DSL Manipulation** [CRITICAL NODE]
│   └───[AND] **Execute Malicious Query via Elasticsearch-PHP** [CRITICAL NODE]
│       ├─── **Application Uses Unsafe Query Building Methods** [CRITICAL NODE]
├───[AND] **Exploit Elasticsearch-PHP Configuration Vulnerabilities** [CRITICAL NODE] [HIGH RISK PATH]
│   ├───[OR] **Hardcoded Credentials in Application Code** [CRITICAL NODE]
│   ├───[AND] **Exploit Weak or Default Credentials** [CRITICAL NODE]
│   │   ├─── **Default Elasticsearch Credentials (if unchanged)** [CRITICAL NODE]
│   └───[AND] **Gain Unauthorized Access to Elasticsearch** [CRITICAL NODE]
│       └─── **Abuse Misconfigured Authorization Rules** [CRITICAL NODE]
└───[AND] **Abuse Elasticsearch-PHP Features for Malicious Purposes** [CRITICAL NODE] [HIGH RISK PATH]
    ├───[OR] **Denial of Service (DoS) via Resource Exhaustion** [CRITICAL NODE]
    │   ├─── **Send Extremely Large or Complex Queries** [CRITICAL NODE]
    │   ├─── **Repeatedly Send Many Requests** [CRITICAL NODE]

Attack Tree Path: Exploit Elasticsearch Query Injection [CRITICAL NODE] [HIGH RISK PATH]

• Attack Vector: User-Controlled Search Parameters [CRITICAL NODE]:

  • Attackers identify input fields in the application (e.g., search boxes, filter inputs, URL parameters) that are used to construct Elasticsearch queries via elasticsearch-php.
  • They inject malicious Elasticsearch query syntax into these input fields.
  • If the application does not properly sanitize or parameterize these inputs, the injected query is executed directly against Elasticsearch.
  • Example Attack Scenarios:
    • Data Exfiltration: Injecting query clauses to bypass intended search filters and retrieve sensitive data they should not have access to.
    • Privilege Escalation: Manipulating queries to access or modify data belonging to other users or roles.
    • Data Manipulation: Injecting update or delete operations (if the application's Elasticsearch user has such permissions, which is a misconfiguration in itself, but possible if combined with other vulnerabilities).
    • Denial of Service (DoS): Crafting resource-intensive queries that overload the Elasticsearch server.

• Attack Vector: Craft Malicious Elasticsearch Query [CRITICAL NODE]:

  • Attackers leverage their knowledge of Elasticsearch's Query DSL (Domain Specific Language) to create malicious query fragments.
  • Attack Sub-Vectors:
    • Inject Malicious Operators/Functions [CRITICAL NODE]:
      • If Elasticsearch scripting is enabled (less common in production due to security risks), attackers attempt to inject scripts (e.g., Painless scripts) to execute arbitrary code on the Elasticsearch server. This can lead to Remote Code Execution (RCE).
      • Attackers may inject malicious aggregation functions to extract sensitive data through aggregations or cause performance issues.
    • Query DSL Manipulation [CRITICAL NODE]:
      • Attackers modify the structure of the Elasticsearch query using DSL features to bypass security filters, access unauthorized data, or perform unintended actions.
      • This could involve manipulating bool queries, filter contexts, or other query clauses to alter the query's logic.

• Attack Vector: Execute Malicious Query via Elasticsearch-PHP [CRITICAL NODE]:

  • Attack Sub-Vectors:
    • Application Uses Unsafe Query Building Methods [CRITICAL NODE]:
      • The application code uses insecure methods to construct Elasticsearch queries, such as direct string interpolation of user inputs into query strings.
      • This makes it trivial for attackers to inject malicious query fragments.
      • Example of Unsafe Code (PHP):

        $searchTerm = $_GET['search'];
        $query = '{ "query": { "match": { "field": "' . $searchTerm . '" } } }'; // VULNERABLE!
        $params = ['index' => 'my_index', 'body' => $query];
        $client->search($params);

    • Elasticsearch-PHP Client Executes Unsanitized Query:
      • Even if the application uses elasticsearch-php, if the query itself is constructed unsafely, the client will faithfully execute the malicious query against the Elasticsearch server.

Attack Tree Path: Exploit Elasticsearch-PHP Configuration Vulnerabilities [CRITICAL NODE] [HIGH RISK PATH]

• Attack Vector: Hardcoded Credentials in Application Code [CRITICAL NODE]:

  • Developers mistakenly embed Elasticsearch credentials (username, password) directly into the application's source code.
  • Attackers can find these credentials through:
    • Static code analysis of the application's codebase (if source code is accessible).
    • Reverse engineering of compiled application binaries.
    • Accidental exposure of code repositories (e.g., public GitHub repositories).
  • Compromised credentials allow direct, unauthorized access to the Elasticsearch server.

• Attack Vector: Exploit Weak or Default Credentials [CRITICAL NODE]:

  • Attack Sub-Vectors:
    • Default Elasticsearch Credentials (if unchanged) [CRITICAL NODE]:
      • Administrators fail to change the default Elasticsearch credentials (e.g., elastic/changeme).
      • Attackers attempt to log in using these default credentials, gaining immediate administrative access to Elasticsearch.
    • Weak Passwords or Predictable Patterns:
      • Administrators set weak or easily guessable passwords for Elasticsearch users.
      • Attackers use password guessing or brute-force techniques to crack these weak passwords and gain unauthorized access.

• Attack Vector: Gain Unauthorized Access to Elasticsearch [CRITICAL NODE]:

  • Attack Sub-Vectors:
    • Abuse Misconfigured Authorization Rules [CRITICAL NODE]:
      • Elasticsearch's role-based access control (RBAC) or other authorization mechanisms are misconfigured.
      • Attackers identify and exploit lax or overly permissive access control policies.
      • This can allow them to bypass intended access restrictions and gain unauthorized access to indices, data, or administrative functions within Elasticsearch.
      • Example Misconfigurations:
        • Granting overly broad permissions to application users.
        • Failing to properly restrict access to sensitive indices or operations.
        • Misconfiguring network access controls, allowing unauthorized network access to Elasticsearch.

Attack Tree Path: Abuse Elasticsearch-PHP Features for Malicious Purposes [CRITICAL NODE] [HIGH RISK PATH]

• Attack Vector: Denial of Service (DoS) via Resource Exhaustion [CRITICAL NODE]:
  • Attackers exploit legitimate Elasticsearch features through elasticsearch-php to cause a Denial of Service.
  • Attack Sub-Vectors:
    • Send Extremely Large or Complex Queries [CRITICAL NODE]:
      • Attackers craft and send queries that are intentionally designed to be computationally expensive and resource-intensive for Elasticsearch to process.
      • Repeatedly sending such queries can overload the Elasticsearch server, consuming CPU, memory, and I/O resources, leading to performance degradation or service outage.
      • Examples of Resource-Intensive Queries:
        • Queries with very large terms aggregations.
        • Queries with deeply nested aggregations.
        • Queries with wildcard or regex queries that match a very large number of terms.
    • Repeatedly Send Many Requests [CRITICAL NODE]:
      • Attackers flood the application with a high volume of Elasticsearch requests through elasticsearch-php.
      • This can overwhelm the application server, the network, and the Elasticsearch server itself, leading to service disruption.
      • This is a classic Distributed Denial of Service (DDoS) attack if launched from multiple sources.