attack-tree.md

Attack Tree Analysis for stackexchange/stackexchange.redis

Objective: Unauthorized Data Access, Modification, or DoS via StackExchange.Redis

Attack Tree Visualization

                                  Attacker's Goal:
                                  Unauthorized Data Access, Modification, or DoS
                                  via StackExchange.Redis
                                  /       |        \
                                 /        |         \
                  -----------------       |          -----------------
                  |                       |          |               |
                  V                       V          V               V
           Data Exfiltration        Data Modification   DoS (part)     Configuration Issues
           /       |       \         /      |      \                      (Implicitly Critical)
          /        |        \       /       |       \
         /         |         \     /        |        \
        V          V          V   V         V         V
  1. Read      2. Scan      3. Lua   4. Write  5. Delete  6. Lua
  Arbitrary   Keys w/o     Script   Arbitrary  Arbitrary  Script
  Keys        Auth         (Read)   Data     Data      (Write/
  [HIGH-RISK] [HIGH-RISK] [HIGH-RISK] [HIGH-RISK] [HIGH-RISK] Delete)
                                             [HIGH-RISK]
                                                            |
                                                            V
                                                            11. High CPU
                                                                Usage (DoS)
                                                                (part of DoS)

Attack Tree Path: Data Exfiltration Branch

• 1. Read Arbitrary Keys [HIGH-RISK]

  • Description: An attacker can read any key in the Redis database, regardless of intended access controls.
  • Underlying Cause (Critical): Lack of input validation and authorization. The application does not properly check if the user is allowed to access the requested key. User-supplied data is used directly to construct the key to be read.
  • Likelihood: High (if the critical vulnerability exists).
  • Impact: High to Very High. Can lead to exposure of sensitive data (API keys, user data, session tokens).
  • Effort: Low to Medium.
  • Skill Level: Low to Medium.
  • Detection Difficulty: Medium to High.

• 2. Scan Keys w/o Auth [HIGH-RISK]

  • Description: An attacker can use the SCAN command (or similar) to discover keys in the Redis database without proper authorization.
  • Underlying Cause (Critical): Lack of input validation and authorization. The application does not restrict the use of SCAN or similar commands to authorized users.
  • Likelihood: High (if the critical vulnerability exists).
  • Impact: Medium to High. Allows attackers to map the Redis keyspace, potentially revealing sensitive information.
  • Effort: Low to Medium.
  • Skill Level: Low to Medium.
  • Detection Difficulty: Medium to High.

• 3. Lua Script (Read) [HIGH-RISK]

  • Description: An attacker can inject malicious code into a Lua script executed by the Redis server, allowing them to read arbitrary data.
  • Underlying Cause (Critical): Lack of input sanitization for Lua scripts. User-supplied data is used directly within Lua scripts without proper escaping or validation.
  • Likelihood: High (if Lua scripts are used and not properly secured).
  • Impact: High to Very High. Similar to (1), but potentially more powerful due to Lua's scripting capabilities.
  • Effort: Medium.
  • Skill Level: Medium to High.
  • Detection Difficulty: High.

Attack Tree Path: Data Modification Branch

• 4. Write Arbitrary Data [HIGH-RISK]

  • Description: An attacker can write data to any key in the Redis database, potentially overwriting existing data or injecting malicious content.
  • Underlying Cause (Critical): Lack of input validation and authorization. Similar to (1), but for write operations.
  • Likelihood: High (if the critical vulnerability exists).
  • Impact: High to Very High. Can lead to data corruption, injection of malicious data, or disruption of application logic.
  • Effort: Low to Medium.
  • Skill Level: Low to Medium.
  • Detection Difficulty: Medium to High.

• 5. Delete Arbitrary Data [HIGH-RISK]

  • Description: An attacker can delete any key in the Redis database.
  • Underlying Cause (Critical): Lack of input validation and authorization. Similar to (1), but for delete operations.
  • Likelihood: High (if the critical vulnerability exists).
  • Impact: High to Very High. Can cause data loss, application errors, or denial of service.
  • Effort: Low to Medium.
  • Skill Level: Low to Medium.
  • Detection Difficulty: Medium to High.

• 6. Lua Script (Write/Delete) [HIGH-RISK]

  • Description: An attacker can inject malicious code into a Lua script to write or delete arbitrary data in the Redis database.
  • Underlying Cause (Critical): Lack of input sanitization for Lua scripts. Similar to (3), but for write/delete operations.
  • Likelihood: High (if Lua scripts are used and not properly secured).
  • Impact: High to Very High. Similar to (4) and (5), but potentially more powerful.
  • Effort: Medium.
  • Skill Level: Medium to High.
  • Detection Difficulty: High.

Attack Tree Path: DoS Branch (part)

• 11. High CPU Usage (DoS)
  • Description: The attacker sends computationally expensive commands to the Redis server.
  • Underlying Cause: Lack of restrictions on expensive commands (e.g., KEYS * on a large dataset, complex Lua scripts) or lack of rate limiting.
  • Likelihood: Medium
  • Impact: Medium to High
  • Effort: Low to Medium
  • Skill Level: Low to Medium
  • Detection Difficulty: Low to Medium

Attack Tree Path: Configuration Issues (Implicitly Critical)

• This entire category represents fundamental security flaws. Examples include:
  • Weak or default Redis passwords.
  • Lack of authentication.
  • Exposing Redis on an insecure port (e.g., directly to the internet).
  • Insufficient resource limits (memory, connections).
  • Running Redis as a privileged user.