Django HTMLParser Vulnerability (CVE-2019-14233)
Summary
CVE-2019-14233: An issue was discovered in Django 1.11.x before 1.11.23, 2.1.x before 2.1.11, and 2.2.x before 2.2.4. Affects py-django across 2 version ranges.
< 1.11.23-r0
>= 58f02c498b659a906e9c30d946bd89bedc4717e5, < 974897759e9afc4cc56fb87e12319fa9697e93c9
Fixed in 1.11.23-r0. How to fix ↓
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Background
Django is a popular web framework written in Python that allows developers to build web applications quickly and efficiently. It provides various tools and libraries for handling web-related tasks, including HTML parsing. However, a vulnerability has been discovered in Django versions 1.11.x, 2.1.x, and 2.2.x that affects the HTMLParser behavior used by the framework. This vulnerability, identified as CVE-2019-14233, can lead to a significant slowdown in the evaluation of certain inputs containing large sequences of nested incomplete HTML entities.
Vulnerability Detail
The vulnerability arises due to the behavior of the underlying HTMLParser in Django. The django.utils.html.strip_tags function, which is responsible for stripping HTML tags from a given input, becomes extremely slow when processing inputs with large sequences of nested incomplete HTML entities. This can potentially result in denial of service (DoS) attacks, as an attacker can craft malicious inputs to cause excessive resource consumption and slow down the application's response time. The vulnerability has a CVSS score of 7.5, indicating a high severity level.
How To Fix
Minimum fixed version
1.11.23-r0
This is the first release that contains the fix.
sudo apk add --upgrade py-djangoTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a workaround, developers can manually modify the strip_tags function in their Django installation to improve its performance. One possible approach is to replace the existing implementation with a more efficient HTML stripping algorithm. However, applying the official patch by upgrading to the recommended Django versions is the recommended solution.
Conclusion
The Django HTMLParser vulnerability (CVE-2019-14233) poses a significant risk to Django applications, potentially leading to denial of service attacks. It is crucial for developers to upgrade their Django installations to the recommended versions and apply the necessary patches. By doing so, they can mitigate the risk and ensure the continued security and performance of their applications. For further assistance and support in vulnerability remediation, please contact DevNack.com.
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FAQ
The vulnerability can be exploited to launch denial of service attacks, causing the application to slow down significantly and potentially impacting its availability.
No, only Django versions 1.11.x, 2.1.x, and 2.2.x are affected. Other versions are not vulnerable to this specific issue.
While the vulnerability has been identified, there are no known public exploits available at the moment. However, it is crucial to apply the necessary patches to mitigate the risk.
Yes, the vulnerability can be exploited remotely by sending specially crafted inputs to the targeted Django application.
There is no evidence of active exploitation in the wild at the moment. However, it is advisable to apply the recommended patches as soon as possible to prevent any potential attacks.
References
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