ESB-2018.0689 - [Debian] python-django: Denial of service - Remote/unauthenticated - 2018-03-09


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             AUSCERT External Security Bulletin Redistribution

                               ESB-2018.0689
                       python-django security update
                               9 March 2018

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        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           python-django
Publisher:         Debian
Operating System:  Debian GNU/Linux 7
Impact/Access:     Denial of Service -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2018-7537 CVE-2018-7536 

Reference:         ESB-2018.0664

Original Bulletin: 
   https://lists.debian.org/debian-lts-announce/2018/03/msg00006.html

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Package        : python-django
Version        : 1.4.22-1+deb7u4
CVE ID         : CVE-2018-7536 CVE-2018-7537


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

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