HTML5 Responsive FAQ <= 2.8.5 - Authenticated Stored Cross-Site Scripting
Strategic Overview
- Status
- Unpatched
- Affected Plugin
- HTML5 Responsive FAQ
- Affected Version
<= 2.8.5- CVSS
- 5.5Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2021-24995
At a glance
CVE-2021-24995 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the HTML5 Responsive FAQ WordPress plugin, affecting versions <= 2.8.5. It carries a CVSS score of 5.5 (reachable over the network; low attack complexity). Exploitation requires an authenticated account. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed November 2021, reported by José Aguilera.
Vulnerability Overview
The HTML5 Responsive FAQ plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 2.8.5 due to insufficient input sanitization and output escaping. This makes it possible for high privilege attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This exploit can occur even when unfiltered_html is disallowed.
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')
Reaching this weakness in HTML5 Responsive FAQ <= 2.8.5 takes any authenticated account. 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. No fixed build of this plugin is recorded for HTML5 Responsive FAQ yet, so installs running <= 2.8.5 stay exposed until the vendor ships one.
Remediation
No known patch available. Please review the vulnerability's details in depth and employ mitigations based on your organization's risk tolerance. It may be best to uninstall the affected software and find a replacement.
How does WordSec protect against this?
The attempt arrives as an ordinary request to HTML5 Responsive FAQ: WordSec's web application firewall inspects request payloads before WordPress loads them. No patched version is recorded yet, which is the case where a filtering layer matters most, because there is nothing to update to.
- Firewall
- Alerts
External References
Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C