CVE-2019-14233 : Security Advisory and Response

Django versions 1.11.x prior to 1.11.23, 2.1.x prior to 2.1.11, and 2.2.x prior to 2.2.4 are affected by a vulnerability that could cause a significant slowdown in processing specific inputs with nested incomplete HTML entities.

Understanding CVE-2019-14233

This CVE identifies a performance issue in Django versions that could lead to processing delays when handling certain types of input data.

What is CVE-2019-14233?

An issue in Django versions 1.11.x before 1.11.23, 2.1.x before 2.1.11, and 2.2.x before 2.2.4 causes the function django.utils.html.strip_tags to experience severe slowdowns with specific input containing extensive sequences of nested incomplete HTML entities.

The Impact of CVE-2019-14233

The vulnerability could result in a significant performance degradation when processing certain types of input data due to the behavior of the underlying HTMLParser.

Technical Details of CVE-2019-14233

This section provides more in-depth technical insights into the vulnerability.

Vulnerability Description

The issue in Django versions leads to a slowdown in the evaluation of inputs containing large sequences of nested incomplete HTML entities due to the behavior of the HTMLParser.

Affected Systems and Versions

Django versions 1.11.x to 1.11.23
Django versions 2.1.x to 2.1.11
Django versions 2.2.x to 2.2.4

Exploitation Mechanism

The vulnerability can be exploited by crafting specific input data with extensive sequences of nested incomplete HTML entities, triggering the slowdown in the strip_tags function.

Mitigation and Prevention

Protecting systems from CVE-2019-14233 involves taking immediate steps and implementing long-term security practices.

Immediate Steps to Take

Update Django to the patched versions (1.11.23, 2.1.11, 2.2.4) to mitigate the vulnerability.
Monitor system performance for any signs of unusual slowdowns that could indicate exploitation.

Long-Term Security Practices

Regularly update Django and other software components to address known vulnerabilities promptly.
Implement input validation mechanisms to prevent the injection of malicious data.

Patching and Updates

Ensure timely application of security patches and updates provided by Django to address CVE-2019-14233.