Key Collision Vulnerability in Django Cache Mechanism
Summary
CVE-2020-13254: An issue was discovered in Django 2.2 before 2.2.13 and 3.0 before 3.0.7. Affects python-django across 2 version ranges.
< 2:2.2.13-1
>= 635d53a86a36cde7866b9caefeb64d809e6bfcd9, < 8093aaa8ff9dd7386a069c6eb49fcc1c5980c033
Fixed in 2:2.2.13-1. How to fix ↓
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Background
Django is a high-level Python web framework that encourages rapid development and clean, pragmatic design. It provides a robust set of features for building web applications, including an ORM, routing, authentication, and caching mechanisms. This vulnerability affects versions 2.2 before 2.2.13 and 3.0 before 3.0.7, where improper key validation in the memcached backend can lead to key collisions and potential data leakage.
Vulnerability Detail
The vulnerability, identified as CVE-2020-13254, arises from the lack of key validation in the memcached backend of Django. When malformed cache keys are passed, they can collide with existing keys, leading to unintended data exposure. This could allow an attacker to access sensitive data stored in the cache, which may include user information or application state. The issue is particularly concerning in multi-tenant environments where data isolation is critical.
How To Fix
Minimum fixed version
2:2.2.13-1
This is the first release that contains the fix.
sudo apt-get install --only-upgrade python-djangoTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, avoid using memcached as a caching backend until the upgrade can be applied. Alternatively, validate cache keys manually to ensure they do not contain malformed data.
Conclusion
CVE-2020-13254 presents a significant risk to applications using Django's memcached backend due to potential data leakage from key collisions. It is crucial to upgrade to the patched versions to mitigate this vulnerability effectively.
See every vulnerability recorded for python-django →
FAQ
CVE-2020-13254 is a vulnerability in Django that allows for key collisions in the memcached backend due to improper key validation, potentially leading to data leakage.
Django versions 2.2 before 2.2.13 and 3.0 before 3.0.7 are affected by this vulnerability.
You can use Vulert's playground at Vulert Scanner to check if your application is affected by this vulnerability without requiring any signup.
The CVSS score for CVE-2020-13254 is 5.9, indicating a moderate level of severity.
If an immediate upgrade is not possible, consider using a different caching backend or implementing manual key validation as a temporary measure.
References
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