PyPi: Django

CVE-2018-7536

Safety vulnerability ID: 35797

This vulnerability was reviewed by experts

The information on this page was manually curated by our Cybersecurity Intelligence Team.

Created at Mar 09, 2018 Updated at Nov 05, 2024
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Advisory

An issue was discovered in Django 2.0 before 2.0.3, 1.11 before 1.11.11, and 1.8 before 1.8.19. The django.utils.html.urlize() function was extremely slow to evaluate certain inputs due to catastrophic backtracking vulnerabilities in two regular expressions (only one regular expression for Django 1.8.x). The urlize() function is used to implement the urlize and urlizetrunc template filters, which were thus vulnerable. See: CVE-2018-7536.

Affected package

django

Latest version: 5.1.3

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

Affected versions

Fixed versions

Vulnerability changelog

===========================

*March 6, 2018*

Django 1.8.19 fixes two security issues in 1.18.18.

CVE-2018-7536: Denial-of-service possibility in ``urlize`` and ``urlizetrunc`` template filters
===============================================================================================

The ``django.utils.html.urlize()`` function was extremely slow to evaluate
certain inputs due to a catastrophic backtracking vulnerability in a regular
expression. The ``urlize()`` function is used to implement the ``urlize`` and
``urlizetrunc`` template filters, which were thus vulnerable.

The problematic regular expression is replaced with parsing logic that behaves
similarly.

CVE-2018-7537: Denial-of-service possibility in ``truncatechars_html`` and ``truncatewords_html`` template filters
==================================================================================================================

If ``django.utils.text.Truncator``'s ``chars()`` and ``words()`` methods were
passed the ``html=True`` argument, they were extremely slow to evaluate certain
inputs due to a catastrophic backtracking vulnerability in a regular
expression. The ``chars()`` and ``words()`` methods are used to implement the
``truncatechars_html`` and ``truncatewords_html`` template filters, which were
thus vulnerable.

The backtracking problem in the regular expression is fixed.


===========================

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Severity Details

CVSS Base Score

MEDIUM 5.3

CVSS v3 Details

MEDIUM 5.3
Attack Vector (AV)
NETWORK
Attack Complexity (AC)
LOW
Privileges Required (PR)
NONE
User Interaction (UI)
NONE
Scope (S)
UNCHANGED
Confidentiality Impact (C)
NONE
Integrity Impact (I)
NONE
Availability Availability (A)
LOW

CVSS v2 Details

MEDIUM 5.0
Access Vector (AV)
NETWORK
Access Complexity (AC)
LOW
Authentication (Au)
NONE
Confidentiality Impact (C)
NONE
Integrity Impact (I)
NONE
Availability Impact (A)
PARTIAL