Ultimate NoFollow <= 1.4.8 - Authenticated (Contributor+) Stored Cross-Site Scripting
Strategic Overview
- Status
- Unpatched
- Affected Plugin
- Ultimate Nofollow
- Affected Version
<= 1.4.8- CVSS
- 5.4Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2021-24817
At a glance
CVE-2021-24817 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Ultimate Nofollow WordPress plugin, affecting versions <= 1.4.8. It carries a CVSS score of 5.4 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Contributor level or above. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed November 2021, reported by Quentin VILLAIN (3wsec).
Vulnerability Overview
The Ultimate NoFollow WordPress plugin through 1.4.8 does not sanitise and escape the href attribute of its shortcodes, allowing users with a role as low as contributor to perform Cross-Site Scripting attacks
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed.
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Reaching this weakness in Ultimate Nofollow <= 1.4.8 takes an account at Contributor level or above. 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 Ultimate Nofollow yet, so installs running <= 1.4.8 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?
An attacker needs Contributor access first, so the firewall sees the attempt as traffic from a logged-in account: 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