Vulnerability · Published Jul 20, 2020 · Assigned by GitHub_M
CVE-2020-15118Cross-Site Scripting in Wagtail
Medium 5.7
In plain English
A medium-severity cross-site scripting in wagtail from wagtail. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 66% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
In Wagtail before versions 2.7.4 and 2.9.3, when a form page type is made available to Wagtail editors through the `wagtail.contrib.forms` app, and the page template is built using Django's standard form rendering helpers such as form.as_p, any HTML tags used within a form field's help text will be rendered unescaped in the page. Allowing HTML within help text is an intentional design decision by Django; however, as a matter of policy Wagtail does not allow editors to insert arbitrary HTML by default, as this could potentially be used to carry out cross-site scripting attacks, including privilege escalation. This functionality should therefore not have been made available to editor-level users. The vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin. Patched versions have been released as Wagtail 2.7.4 (for the LTS 2.7 branch) and Wagtail 2.9.3 (for the current 2.9 branch). In these versions, help text will be escaped to prevent the inclusion of HTML tags. Site owners who wish to re-enable the use of HTML within help text (and are willing to accept the risk of this being exploited by editors) may set WAGTAILFORMS_HELP_TEXT_ALLOW_HTML = True in their configuration settings. Site owners who are unable to upgrade to the new versions can secure their form page templates by rendering forms field-by-field as per Django's documentation, but omitting the |safe filter when outputting the help text.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | wagtail | 2.9.3 | GHSA-2473-9hgq-j7xw |
| PyPI | wagtail | 2.7.4 | GHSA-2473-9hgq-j7xw |
| PyPI | wagtail | 2.7.4, 2.9.3 | PYSEC-2020-154 |
Affected products (as reported)
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N
References
- https://github.com/wagtail/wagtail/security/advisories/GHSA-2473-9hgq-j7xw x_refsource_CONFIRM
- https://docs.djangoproject.com/en/3.0/ref/models/fields/#django.db.models.Field.help_text x_refsource_MISC
- https://docs.wagtail.io/en/stable/reference/contrib/forms/index.html#usage x_refsource_MISC
- https://github.com/wagtail/wagtail/commit/d9a41e7f24d08c024acc9a3094940199df94db34 x_refsource_MISC
- https://github.com/wagtail/wagtail/blob/master/docs/releases/2.9.3.rst x_refsource_MISC