Incorrect Permission Assignment for Critical Resource vulnerability in Drupal S3 File System allows Exploiting

1. Implementation

   When using a critical resource such as a configuration file, check to see if the resource has insecure permissions (such as being modifiable by any regular user), and generate an error or even exit the software if there is a possibility that the resource could have been modified by an unauthorized party.

2. Architecture and Design

   Divide the software into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully defining distinct user groups, privileges, and/or roles. Map these against data, functionality, and the related resources. Then set the permissions accordingly.

3. Architecture and Design · Operation · Sandbox or Jail

   Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.

OWASP Cheat Sheets

• REST Assessment (opens in a new tab)
• Authorization (opens in a new tab)

OWASP ASVS 4.0.3

• V4.3.3 (opens in a new tab)
• V8.3.8 (opens in a new tab)
• V13.4.2 (opens in a new tab)

Attack patterns

• Accessing Functionality Not Properly Constrained by ACLs (opens in a new tab)
• Directory Indexing (opens in a new tab)
• Using Malicious Files (opens in a new tab)
• Exploiting Incorrectly Configured Access Control Security Levels (opens in a new tab)
• Signing Malicious Code (opens in a new tab)

From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).