CVE-2021-24159

Contact Form 7 Style <= 3.1.9 Cross-Site Request Forgery

2021-02-04 00:00
Chloe Chamberland

Strategic Overview

Status
Unpatched
Affected Plugin
Contact Form 7 Style
Affected Version
<= 3.1.9
CVSS
8.8High
Weakness type
CWE-352 · Cross-Site Request Forgery (CSRF)
CVE
CVE-2021-24159
View all Contact Form 7 Style vulnerabilities

At a glance

CVE-2021-24159 is a high-severity Cross-Site Request Forgery (CSRF) vulnerability in the Contact Form 7 Style WordPress plugin, affecting versions <= 3.1.9. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed February 2021, reported by Chloe Chamberland.

Vulnerability Overview

Due to the lack of sanitization and lack of nonce protection on the custom CSS feature, an attacker could craft a request to inject malicious JavaScript on a site using the Contact Form 7 Style WordPress plugin through 3.1.9. If an attacker successfully tricked a site’s administrator into clicking a link or attachment, then the request could be sent and the CSS settings would be successfully updated to include malicious JavaScript.

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 privileges on the target site. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-352: Cross-Site Request Forgery (CSRF)

Reaching this weakness in Contact Form 7 Style <= 3.1.9 takes a caller who can reach the endpoint. Cross-site request forgery abuses the fact that browsers attach a victim's cookies to any request, so a state-changing action that only checks who you are, not whether you meant to act, can be triggered from another site.

An attacker who gets a logged-in user to load a crafted page can perform that action as them, with the impact scaling to whatever the victim's role is allowed to do. No fixed build of this plugin is recorded for Contact Form 7 Style yet, so installs running <= 3.1.9 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 Contact Form 7 Style: 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

Related records

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