CVE-2025-31821: Zoho CRM Contact Form 7 Open Redirect

CVE-2025-31821 Overview

CVE-2025-31821 is an open redirect vulnerability in the Integration of Zoho CRM and Contact Form 7 WordPress plugin developed by formsintegrations. The flaw affects all versions up to and including 1.0.6. It falls under [CWE-601] (URL Redirection to Untrusted Site) and enables attackers to craft URLs that redirect victims from a trusted WordPress site to attacker-controlled destinations. The vulnerability requires user interaction, typically clicking a manipulated link, and supports phishing and credential harvesting campaigns.

Critical Impact
Attackers can leverage the trusted domain of a vulnerable WordPress site to redirect users to phishing pages, bypassing user trust indicators and URL-based email filtering.

Affected Products

WordPress plugin: Integration of Zoho CRM and Contact Form 7
Vendor: formsintegrations
Versions: all releases from n/a through 1.0.6

Discovery Timeline

2025-04-01 - CVE-2025-31821 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-31821

Vulnerability Analysis

The plugin accepts a redirect target from a user-controlled parameter and forwards the browser to that destination without validating the target against an allowlist of trusted hosts. Because the redirection is issued by the WordPress site itself, the resulting URL displays a legitimate domain in emails, chat messages, and browser previews before the redirect fires. This weakness supports phishing operations, malware delivery lures, and OAuth or SSO flow abuse where the initial hostname is inspected by security controls or end users.

The Exploit Prediction Scoring System (EPSS) probability for CVE-2025-31821 is 0.406%. No public proof-of-concept exploit and no evidence of exploitation in the wild have been reported.

Root Cause

The root cause is missing validation of a redirect URL parameter. The plugin trusts external input and passes it directly to a redirect function without enforcing a domain allowlist, relative-path constraint, or signed redirect token. This pattern is the standard [CWE-601] anti-pattern seen across WordPress plugin ecosystems.

Attack Vector

An unauthenticated attacker crafts a URL pointing to the vulnerable WordPress site with a redirect parameter set to a malicious destination. The attacker distributes the link through email, social media, SMS, or malicious advertising. When the victim clicks the link, the WordPress site issues an HTTP redirect response, and the browser follows the redirect to the attacker-controlled site. The destination site typically imitates a login page, payment form, or software update prompt.

Refer to the Patchstack Vulnerability Report for the vendor-tracked technical details.

Detection Methods for CVE-2025-31821

Indicators of Compromise

Web server access logs containing requests to plugin endpoints with external URLs in query string parameters such as redirect, url, return, or next.
HTTP 301 or 302 responses from the WordPress site with Location headers pointing to domains outside the site's own hostname.
Referer headers in downstream systems showing traffic originating from the vulnerable WordPress path before landing on unknown external hosts.

Detection Strategies

Inspect web server logs for query strings containing full URLs (http://, https://, or protocol-relative //) targeted at plugin request handlers.
Correlate outbound redirects from the WordPress site with domain reputation feeds and newly registered domains.
Monitor email security gateways for messages containing links to the affected WordPress domain with suspicious redirect parameters.

Monitoring Recommendations

Enable and retain WordPress access logs and reverse-proxy logs for at least 90 days to support retrospective analysis.
Alert on any HTTP redirect issued by the site where the Location header host does not match the site's canonical domain.
Track user reports of unexpected redirects from links that appear to originate from the trusted site.

How to Mitigate CVE-2025-31821

Immediate Actions Required

Update the Integration of Zoho CRM and Contact Form 7 plugin to a version later than 1.0.6 once a patched release is available from formsintegrations.
Audit all outbound links from the WordPress site to identify content that may already be abused for redirection.
Notify users and staff about phishing campaigns that abuse the trusted domain, and reinforce credential hygiene.

Patch Information

No fixed version is listed in the NVD entry at the time of publication. Administrators should consult the Patchstack Vulnerability Report and the plugin's WordPress repository page for updated release information and apply the vendor patch as soon as it becomes available.

Workarounds

Deactivate and remove the plugin until a patched version is released if the integration is not business-critical.
Deploy a web application firewall (WAF) rule that blocks requests to plugin endpoints when redirect parameters contain external URLs or protocol-relative paths.
Restrict access to the plugin's redirect handler at the reverse proxy or .htaccess layer to internal networks only, if the endpoint is not required for public workflows.

bash

# Example WAF rule (ModSecurity) to block external redirect targets
SecRule REQUEST_URI "@contains /wp-content/plugins/integration-of-zoho-crm-and-contact-form-7/" \
  "chain,id:1003182,phase:2,deny,status:403,msg:'CVE-2025-31821 open redirect attempt'"
  SecRule ARGS "@rx ^(https?:)?//" "t:none,t:urlDecodeUni"