Debian Security Advisory

DLA-1303-1 python-django -- LTS security update

Date Reported:
08 Mar 2018
Affected Packages:
python-django
Vulnerable:
Yes
Security database references:
In Mitre's CVE dictionary: CVE-2018-7536, CVE-2018-7537.
More information:

Several functions were extremely slow to evaluate certain inputs due to catastrophic backtracking vulnerabilities in several regular expressions.

  • CVE-2018-7536

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

    The problematic regular expressions are replaced with parsing logic that behaves similarly.

  • CVE-2018-7537

    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.

For Debian 7 Wheezy, these problems have been fixed in version 1.4.22-1+deb7u4.

We recommend that you upgrade your python-django packages.

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: https://wiki.debian.org/LTS