CVE-2021-24247

Contact Form Check Tester <= 1.0.2 - Authenticated (Subscriber+) Cross-Site Scripting

2021-04-10 00:00
0xB9

Strategic Overview

Status
Unpatched
Affected Version
<= 1.0.2
CVSS
6.4Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2021-24247
View all Contact Form Check Tester vulnerabilities

At a glance

CVE-2021-24247 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Contact Form Check Tester WordPress plugin, affecting versions <= 1.0.2. It carries a CVSS score of 6.4 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Subscriber level or above. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed April 2021, reported by 0xB9.

Vulnerability Overview

The Contact Form Check Tester WordPress plugin through 1.0.2 settings are visible to all registered users in the dashboard and are lacking any sanitisation. As a result, any registered user, such as subscriber, can leave an XSS payload in the plugin settings, which will be triggered by any user visiting them, and could allow for privilege escalation. The vendor decided to close the plugin.

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 Contact Form Check Tester <= 1.0.2 takes an account at Subscriber 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 Contact Form Check Tester yet, so installs running <= 1.0.2 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 Subscriber 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