attack-tree.md

Attack Tree Analysis for nikic/php-parser

Objective: Execute arbitrary code on the server or exfiltrate sensitive data via php-parser exploitation

Attack Tree Visualization

Goal: Execute arbitrary code on the server or exfiltrate sensitive data via php-parser exploitation

├── 1. Uncontrolled Code Generation (Remote Code Execution - RCE) [HIGH RISK] │ ├── 1.1 Manipulate AST to Inject Malicious Code [HIGH RISK] │ │ ├── 1.1.1 Input Validation Bypass (Parser Input) [CRITICAL] │ │ │ ├── 1.1.1.1 Exploit parser bugs to bypass input sanitization. │ │ │ └── 1.1.1.2 Inject specially crafted code (syntactically valid, unexpected behavior). │ │ ├── 1.1.2 Abuse AST Modification Features [HIGH RISK] │ │ │ ├── 1.1.2.1 Inject malicious nodes via user-controlled AST modification. [HIGH RISK] [CRITICAL] │ │ └── 1.1.3 Template Injection in Code Generation [HIGH RISK] │ │ ├── 1.1.3.1 Inject malicious code into the template. [HIGH RISK] [CRITICAL] │ └── 1.2 Deserialization of Untrusted Data (if applicable) [HIGH RISK] │ ├── 1.2.1 Inject a malicious serialized object. [HIGH RISK] [CRITICAL]

├── 2. Information Disclosure / Data Exfiltration │ ├── 2.1 Leak Sensitive Information via Error Messages │ │ ├── 2.1.1 Trigger parser errors to reveal sensitive information. [CRITICAL] │ └── 2.2 Access Sensitive Data Through AST Traversal │ ├── 2.2.1 Extract sensitive data from parsed code. [CRITICAL]

├── 3. Denial of Service (DoS) ├── 3.1 Resource Exhaustion via Complex Input │ ├── 3.1.1 Provide deeply nested or large code structures. [CRITICAL] └── 3.2 Regular Expression Denial of Service (ReDoS) ├── 3.2.1 Craft input that triggers catastrophic backtracking. [CRITICAL]

Attack Tree Path: 1. Uncontrolled Code Generation (RCE) [HIGH RISK]

1. Uncontrolled Code Generation (RCE) [HIGH RISK]

• 1.1 Manipulate AST to Inject Malicious Code [HIGH RISK]

  • 1.1.1 Input Validation Bypass (Parser Input) [CRITICAL]

    • Description: The attacker circumvents input validation mechanisms to provide malicious input to the parser.
    • Sub-Vectors:
      • 1.1.1.1 Exploit parser bugs: The attacker finds and exploits a bug in the php-parser library itself that allows them to bypass intended input sanitization. This could involve crafting input that triggers unexpected behavior in the parser's lexer or parser components.
        • Likelihood: Medium
        • Impact: Very High (RCE)
        • Effort: Medium to High
        • Skill Level: Advanced
        • Detection Difficulty: Medium to Hard
      • 1.1.1.2 Inject specially crafted code: The attacker provides code that is syntactically valid PHP but, when parsed and processed by the application, results in unintended behavior, potentially leading to code execution. This relies on exploiting the application's logic that uses the parser's output.
        • Likelihood: Medium
        • Impact: Very High (RCE)
        • Effort: Medium to High
        • Skill Level: Advanced to Expert
        • Detection Difficulty: Hard

  • 1.1.2 Abuse AST Modification Features [HIGH RISK]

    • Description: The application allows modification of the Abstract Syntax Tree (AST) based on user input, and the attacker exploits this to inject malicious code.
    • Sub-Vectors:
      • 1.1.2.1 Inject malicious nodes via user-controlled AST modification [HIGH RISK] [CRITICAL]: The attacker directly provides data that is used to create or modify nodes in the AST, leading to the insertion of malicious code that will be executed when the AST is traversed or used to generate code.
        • Likelihood: High (If AST modification is exposed to user input)
        • Impact: Very High (RCE)
        • Effort: Low to Medium
        • Skill Level: Intermediate to Advanced
        • Detection Difficulty: Medium

  • 1.1.3 Template Injection in Code Generation [HIGH RISK]

    • Description: The application uses php-parser to generate code from templates, and the attacker injects malicious code into the template.
    • Sub-Vectors:
      • 1.1.3.1 Inject malicious code into the template [HIGH RISK] [CRITICAL]: The attacker manipulates the template content, inserting PHP code that will be executed when the template is processed and code is generated.
        • Likelihood: Medium to High (If templates are not properly sanitized)
        • Impact: Very High (RCE)
        • Effort: Low to Medium
        • Skill Level: Intermediate
        • Detection Difficulty: Medium

• 1.2 Deserialization of Untrusted Data (if applicable) [HIGH RISK]

  • Description: The application deserializes data that originated from, or was influenced by, user input, potentially leading to code execution.
  • Sub-Vectors:
    • 1.2.1 Inject a malicious serialized object [HIGH RISK] [CRITICAL]: The attacker provides a crafted serialized PHP object that, when unserialized, triggers the execution of malicious code through magic methods (e.g., __wakeup(), __destruct()) or other vulnerabilities in the deserialization process.
      • Likelihood: High (If unserialization of untrusted data is used)
      • Impact: Very High (RCE)
      • Effort: Low to Medium
      • Skill Level: Intermediate
      • Detection Difficulty: Medium

Attack Tree Path: 2. Information Disclosure / Data Exfiltration

2. Information Disclosure / Data Exfiltration

• 2.1 Leak Sensitive Information via Error Messages

  • Description: The attacker triggers errors in the parser or the application's handling of the parser's output, causing sensitive information to be revealed in error messages.
  • Sub-Vectors:
    • 2.1.1 Trigger parser errors to reveal sensitive information [CRITICAL]: The attacker provides malformed or unexpected input that causes the parser to throw errors that expose internal details, such as file paths, code snippets, or configuration information.
      • Likelihood: Medium
      • Impact: Medium to High
      • Effort: Low
      • Skill Level: Novice to Intermediate
      • Detection Difficulty: Easy

• 2.2 Access Sensitive Data Through AST Traversal

  • Description: The attacker gains access to sensitive data stored within the code being parsed by exploiting the application's use of AST traversal.
  • Sub-Vectors:
    • 2.2.1 Extract sensitive data from parsed code [CRITICAL]: If the application parses code that contains sensitive data (e.g., hardcoded credentials, API keys), the attacker can use the AST traversal features of php-parser to extract this information.
      • Likelihood: Medium (If sensitive data is present in parsed code)
      • Impact: High
      • Effort: Low to Medium
      • Skill Level: Intermediate
      • Detection Difficulty: Medium

Attack Tree Path: 3. Denial of Service (DoS)

3. Denial of Service (DoS)

• 3.1 Resource Exhaustion via Complex Input

  • Description: The attacker provides input designed to consume excessive resources (CPU, memory) during parsing, leading to a denial of service.
  • Sub-Vectors:
    • 3.1.1 Provide deeply nested or large code structures [CRITICAL]: The attacker submits code with deeply nested structures (e.g., arrays, objects, function calls) or extremely large strings, causing the parser to consume excessive memory or CPU time, potentially crashing the application or making it unresponsive.
      • Likelihood: Medium to High (If no input limits are in place)
      • Impact: Medium
      • Effort: Low
      • Skill Level: Novice
      • Detection Difficulty: Easy

• 3.2 Regular Expression Denial of Service (ReDoS)

  • Description: The attacker exploits vulnerabilities in regular expressions used by the parser (or the application) to cause catastrophic backtracking, leading to a denial of service.
  • Sub-Vectors:
    • 3.2.1 Craft input that triggers catastrophic backtracking [CRITICAL]: The attacker provides input that matches a vulnerable regular expression in a way that causes the regex engine to enter a state of excessive backtracking, consuming significant CPU time and potentially making the application unresponsive.
      • Likelihood: Low to Medium
      • Impact: Medium
      • Effort: Medium
      • Skill Level: Intermediate to Advanced
      • Detection Difficulty: Medium