CVE-2024-53907
📋 TL;DR
This vulnerability in Django's strip_tags() method and striptags template filter allows attackers to cause denial-of-service by sending specially crafted inputs with large sequences of nested incomplete HTML entities. It affects all Django applications using these functions in versions 4.2 before 4.2.17, 5.0 before 5.0.10, and 5.1 before 5.1.4.
💻 Affected Systems
- Django
📦 What is this software?
Django by Djangoproject
Django by Djangoproject
Django by Djangoproject
⚠️ Risk & Real-World Impact
Worst Case
Complete service unavailability due to resource exhaustion, potentially affecting all users of the Django application.
Likely Case
Degraded performance or temporary service disruption for affected endpoints processing user input through strip_tags() or striptags.
If Mitigated
Minimal impact with proper input validation, rate limiting, and updated Django versions.
🎯 Exploit Status
The vulnerability is simple to exploit as it only requires sending malicious input to endpoints using affected functions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Django 4.2.17, 5.0.10, or 5.1.4
Vendor Advisory: https://docs.djangoproject.com/en/dev/releases/security/
Restart Required: Yes
Instructions:
1. Check current Django version with 'python -m django --version'. 2. Upgrade using pip: 'pip install Django==4.2.17' or 'pip install Django==5.0.10' or 'pip install Django==5.1.4'. 3. Restart your Django application server.
🔧 Temporary Workarounds
Input Validation Workaround
allImplement custom input validation to limit HTML entity sequences before passing to strip_tags()
# Python example
import re
from django.utils.html import strip_tags
def safe_strip_tags(text):
# Limit nested entities
if re.search(r'&[a-zA-Z0-9#]+;{100,}', text):
return ''
return strip_tags(text)
🧯 If You Can't Patch
- Implement WAF rules to block requests containing excessive HTML entity sequences
- Apply rate limiting to endpoints using strip_tags() or striptags functions
🔍 How to Verify
Check if Vulnerable:
Check Django version: 'python -m django --version'. If version is 4.2.x < 4.2.17, 5.0.x < 5.0.10, or 5.1.x < 5.1.4, you are vulnerable.Check Version:
python -m django --versionVerify Fix Applied:
After patching, verify version shows 4.2.17, 5.0.10, or 5.1.4 and test strip_tags() with malicious input containing nested HTML entities.📡 Detection & Monitoring
Log Indicators:
- Unusually long processing times for requests containing HTML input
- High CPU/memory usage spikes when processing form submissions
Network Indicators:
- Repeated requests with long strings containing '&' characters and semicolons
- Traffic patterns showing DoS attempts against Django endpoints
SIEM Query:
source="django.log" AND (message="strip_tags" OR message="striptags") AND duration>5s