XSS in Torchbox Wagtail
CVE-2020-15118
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.7 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.011 (64.4th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 64.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000
Affected products
- Torchbox Wagtail
- Wagtail — versions < 2.7.4, >= 2.8.0, < 2.9.3
Weakness classification (CWE)
References
- github.com/wagtail/wagtail/security/advisories/GHSA-2473-9hgq-j7xw (Third Party Advisory)
- docs.djangoproject.com/en/3.0/ref/models/fields/ (Third Party Advisory)
- docs.wagtail.io/en/stable/reference/contrib/forms/index.html (Vendor Advisory)
- github.com/wagtail/wagtail/commit/d9a41e7f24d08c024acc9a3094940199df94db34 (Patch, Third Party Advisory)
- github.com/wagtail/wagtail/blob/master/docs/releases/2.9.3.rst (Third Party Advisory, Release Notes)
Frequently asked questions
- What is CVE-2020-15118?
- CVE-2020-15118 is a medium-severity vulnerability in Torchbox Wagtail, classified under Cross-site Scripting. CVSS score: 5.7/10. Published 2020-07-20.
- How severe is CVE-2020-15118?
- Medium severity. CVSS v3 base score is 5.7 out of 10.