ghsa-2473-9hgq-j7xw
Vulnerability from github
Published
2020-07-20 17:50
Modified
2024-11-19 15:50
Severity ?
5.7 (Medium) - CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N
7.2 (High) - CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Summary
Cross-Site Scripting in Wagtail
Details

Impact

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 (as directed in the documentation), 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.

Patches

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.

Workarounds

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.

Acknowledgements

Many thanks to Timothy Bautista for reporting this issue.

For more information

If you have any questions or comments about this advisory: * Visit Wagtail's support channels * Email us at security@wagtail.io (if you wish to send encrypted email, the public key ID is 0x6ba1e1a86e0f8ce8)

Show details on source website

To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "wagtail"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.8rc1"
            },
            {
              "fixed": "2.9.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "wagtail"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.7.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2020-15118"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2020-07-20T17:47:32Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\nWhen a form page type is made available to Wagtail editors through the `wagtail.contrib.forms` app, and the page template is built using Django\u0027s standard form rendering helpers such as `form.as_p` ([as directed in the documentation](https://docs.wagtail.io/en/stable/reference/contrib/forms/index.html#usage)), any HTML tags used within a form field\u0027s help text will be rendered unescaped in the page. Allowing HTML within help text is [an intentional design decision](https://docs.djangoproject.com/en/3.0/ref/models/fields/#django.db.models.Field.help_text) 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.\n\nThe vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin.\n\n### Patches\nPatched 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.\n\n### Workarounds\nSite 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\u0027s documentation](https://docs.djangoproject.com/en/3.0/topics/forms/#looping-over-the-form-s-fields), but omitting the `|safe` filter when outputting the help text.\n\n### Acknowledgements\nMany thanks to Timothy Bautista for reporting this issue.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Visit Wagtail\u0027s [support channels](https://docs.wagtail.io/en/stable/support.html)\n* Email us at [security@wagtail.io](mailto:security@wagtail.io) (if you wish to send encrypted email, the public key ID is `0x6ba1e1a86e0f8ce8`)",
  "id": "GHSA-2473-9hgq-j7xw",
  "modified": "2024-11-19T15:50:10Z",
  "published": "2020-07-20T17:50:30Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/wagtail/wagtail/security/advisories/GHSA-2473-9hgq-j7xw"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-15118"
    },
    {
      "type": "WEB",
      "url": "https://github.com/wagtail/wagtail/commit/d9a41e7f24d08c024acc9a3094940199df94db34"
    },
    {
      "type": "WEB",
      "url": "https://docs.djangoproject.com/en/3.0/ref/models/fields/#django.db.models.Field.help_text"
    },
    {
      "type": "WEB",
      "url": "https://docs.wagtail.io/en/stable/reference/contrib/forms/index.html#usage"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/wagtail/PYSEC-2020-154.yaml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/wagtail/wagtail"
    },
    {
      "type": "WEB",
      "url": "https://github.com/wagtail/wagtail/blob/master/docs/releases/2.9.3.rst"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Cross-Site Scripting in Wagtail"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.