CVE-2021-26540 Information

Description

Apostrophe Technologies sanitize-html before 2.3.2 does not properly validate the hostnames set by the llowedIframeHostnames\ option when the llowIframeRelativeUrls\ 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 Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Reference

https://github.com/apostrophecms/sanitize-html/blob/main/CHANGELOG.md#232-2021-01-26 https://github.com/apostrophecms/sanitize-html/pull/460 https://advisory.checkmarx.net/advisory/CX-2021-4309

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

LOW

Base Score

NONE

Base Severity

5.3