Contact Form by Supsystic < 1.7.20 - Authenticated (Admin+) Stored Cross-Site Scripting

2021-10-28 00:00
Murat DEMIRCI

Strategic Overview

Status
Patched in 1.7.20
Affected Plugin
Contact Form by Supsystic
Affected Version
< 1.7.20
CVSS
5.5Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE pending
View all Contact Form by Supsystic vulnerabilities

At a glance

This record tracks a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Contact Form by Supsystic WordPress plugin, affecting versions < 1.7.20. It carries a CVSS score of 5.5 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Admin level or above. The issue is fixed in version 1.7.20; sites on affected versions should update now. Disclosed October 2021, reported by Murat DEMIRCI.

Vulnerability Overview

The Contact Form by Supsystic plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the fields label in versions before 1.7.20 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers with admin-level privileges to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

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 by Supsystic < 1.7.20 takes an account at Admin 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. For Contact Form by Supsystic the fix is 1.7.20: builds < 1.7.20 are affected, anything from 1.7.20 onward is not.

Remediation

Update to version 1.7.20, or a newer patched version

How does WordSec protect against this?

An attacker needs Admin 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. None of that substitutes for the fix: Contact Form by Supsystic 1.7.20 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/6e53e70f-45fc-41a6-8436-a8b14f7685d0

Related records

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