Vulnerability Description
Apostrophe Technologies sanitize-html before 2.3.2 does not properly validate the hostnames set by the "allowedIframeHostnames" option when the "allowIframeRelativeUrls" is set to true, which allows attackers to bypass hostname whitelist for iframe element, related using an src value that starts with "/\\example.com".
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Apostrophecms | Sanitize-Html | < 2.3.2 |
References
- https://advisory.checkmarx.net/advisory/CX-2021-4309ExploitPatchThird Party Advisory
- https://github.com/apostrophecms/sanitize-html/blob/main/CHANGELOG.md#232-2021-0Release NotesThird Party Advisory
- https://github.com/apostrophecms/sanitize-html/pull/460PatchThird Party Advisory
- https://advisory.checkmarx.net/advisory/CX-2021-4309ExploitPatchThird Party Advisory
- https://github.com/apostrophecms/sanitize-html/blob/main/CHANGELOG.md#232-2021-0Release NotesThird Party Advisory
- https://github.com/apostrophecms/sanitize-html/pull/460PatchThird Party Advisory
FAQ
What is CVE-2021-26540?
CVE-2021-26540 is a vulnerability with a CVSS score of 5.3 (MEDIUM). Apostrophe Technologies sanitize-html before 2.3.2 does not properly validate the hostnames set by the "allowedIframeHostnames" option when the "allowIframeRelativeUrls" is set to true, which allows a...
How severe is CVE-2021-26540?
CVE-2021-26540 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-26540?
Check the references section above for vendor advisories and patch information. Affected products include: Apostrophecms Sanitize-Html.