CVE-2025-39480 – This vulnerability allows attackers to execute ... (How to Fix)

📋 TL;DR

This vulnerability allows attackers to execute arbitrary code on WordPress sites using the Car Dealer theme by exploiting insecure deserialization. It affects all WordPress installations running Car Dealer theme versions up to 1.6.6, potentially compromising the entire website.

💻 Affected Systems

Products:

ThemeMakers Car Dealer WordPress Theme

Versions: All versions up to and including 1.6.6

Operating Systems: All operating systems running WordPress

Default Config Vulnerable: ⚠️ Yes

Notes: Requires WordPress with Car Dealer theme installed and activated

⚠️ Manual Verification Required

This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.

Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).

🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.

Recommended Actions:

Review the CVE details at NVD
Check vendor security advisories for your specific version
Test if the vulnerability is exploitable in your environment
Consider updating to the latest version as a precaution

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete server compromise leading to data theft, malware installation, and use as attack platform

🟠

Likely Case

Website defacement, admin access takeover, and backdoor installation

🟢

If Mitigated

Limited impact if proper input validation and WAF rules block exploitation attempts

🌐 Internet-Facing: HIGH

🏢 Internal Only: MEDIUM

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Public exploit details available on Patchstack; simple HTTP requests can trigger the vulnerability

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 1.6.7 or later

Vendor Advisory: https://patchstack.com/database/wordpress/theme/cardealer/vulnerability/wordpress-car-dealer-1-6-6-php-object-injection-vulnerability?_s_id=cve

Restart Required: No

Instructions:

1. Log into WordPress admin panel
2. Navigate to Appearance > Themes
3. Check for Car Dealer theme update notification
4. Click Update Now
5. Verify theme version is 1.6.7 or higher

🔧 Temporary Workarounds

Disable vulnerable theme

all

Switch to default WordPress theme to remove attack surface

wp theme activate twentytwentyfour

WAF rule blocking

all

Block serialized object patterns in HTTP requests

Add WAF rule: Block requests containing O: and C: patterns in POST data

🧯 If You Can't Patch

Disable Car Dealer theme immediately and use alternative theme
Implement strict input validation and sanitization for all user inputs

🔍 How to Verify

Check if Vulnerable:

Check WordPress admin panel > Appearance > Themes > Car Dealer version

Check Version:

wp theme list --name=cardealer --field=version

Verify Fix Applied:

Confirm Car Dealer theme version is 1.6.7 or higher

📡 Detection & Monitoring

Log Indicators:

Unusual POST requests to theme files
PHP unserialize() errors in logs
Unexpected file creation in wp-content

Network Indicators:

HTTP requests containing serialized PHP objects (O:8:, C:11: patterns)
Traffic to unfamiliar admin-ajax.php endpoints

SIEM Query:

source=web_logs AND ("O:8:" OR "C:11:" OR "unserialize") AND uri_path="*/cardealer/*"

📊 Metadata

CVE ID: CVE-2025-39480

CVSS v3 Score: 9.8 (CRITICAL)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-502

EPSS Score: 0.13% exploit probability (33.2th percentile)

Published: May 23, 2025

Last Updated: May 23, 2025

🔗 References

https://patchstack.com/database/wordpress/theme/cardealer/vulnerability/wordpress-car-dealer-1-6-6-php-object-injection-vulnerability?_s_id=cve

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