Strategic Overview
- Status
- Patched in 1.2.4
- Affected Plugin
- WP Page Builder
- Affected Version
< 1.2.4- CVSS
- 7.4High
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2021-24208
At a glance
CVE-2021-24208 is a high-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the WP Page Builder WordPress plugin, affecting versions < 1.2.4. It carries a CVSS score of 7.4 (reachable over the network; low attack complexity). The issue is fixed in version 1.2.4; sites on affected versions should update now. Disclosed April 2021, reported by Ram.
Vulnerability Overview
The editor of the WP Page Builder WordPress plugin before 1.2.4 allows lower-privileged users to insert unfiltered HTML, including JavaScript, into pages via the “Raw HTML” widget and the “Custom HTML” widgets (though the custom HTML widget requires sending a crafted request - it appears that this widget uses some form of client side validation but not server side validation), all of which are added via the “page_builder_data” parameter when performing the “wppb_page_save” AJAX action. It is also possible to insert malicious JavaScript via the “wppb_page_css” parameter (this can be done by closing out the style tag and opening a script tag) when performing the “wppb_page_save” AJAX action.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user.
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
WP Page Builder < 1.2.4 carries this weakness at page_builder_data, and reaching it takes a caller who can reach the endpoint. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.
Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For WP Page Builder the fix is 1.2.4: builds < 1.2.4 are affected, anything from 1.2.4 onward is not.
Remediation
Update to version 1.2.4, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to WP Page Builder: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: WP Page Builder 1.2.4 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Related records
Same weakness class
Other vulnerabilities in WP Page Builder
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