CVE-2023-7027 – This vulnerability allows unauthenticated attac... (How to Fix)

Q: What is the severity of CVE-2023-7027?

CVE-2023-7027 has a CVSS score of 7.2 (HIGH). This vulnerability allows unauthenticated attackers to inject malicious scripts into WordPress sites using the POST SMTP Mailer plugin. When users visit pages containing the injected scripts, arbitrary code executes in their browsers. All WordPress sites running vulnerable plugin versions are affected.

📋 TL;DR

This vulnerability allows unauthenticated attackers to inject malicious scripts into WordPress sites using the POST SMTP Mailer plugin. When users visit pages containing the injected scripts, arbitrary code executes in their browsers. All WordPress sites running vulnerable plugin versions are affected.

💻 Affected Systems

Products:

POST SMTP Mailer WordPress plugin

Versions: All versions up to and including 2.8.7

Operating Systems: Any OS running WordPress

Default Config Vulnerable: ⚠️ Yes

Notes: Affects all WordPress installations with the vulnerable plugin enabled. No special configuration required.

📦 What is this software?

Post Smtp by Wpexperts

View all CVEs affecting Post Smtp →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Attackers could steal administrator credentials, redirect users to malicious sites, deface websites, or perform actions on behalf of authenticated users.

🟠

Likely Case

Attackers will inject malicious scripts to steal session cookies, redirect users to phishing sites, or display unwanted advertisements.

🟢

If Mitigated

With proper web application firewalls and input validation, the risk is reduced to minimal impact with blocked malicious payloads.

🌐 Internet-Facing: HIGH

🏢 Internal Only: MEDIUM

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploitation requires sending specially crafted HTTP requests with malicious 'device' headers. Public exploit details are available.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 2.8.8

Vendor Advisory: https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=3016126%40post-smtp%2Ftrunk&old=3012318%40post-smtp%2Ftrunk&sfp_email=&sfph_mail=

Restart Required: No

Instructions:

1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find POST SMTP Mailer plugin. 4. Click 'Update Now' if available. 5. Alternatively, download version 2.8.8+ from WordPress repository and manually update.

🔧 Temporary Workarounds

Web Application Firewall (WAF)

all

Configure WAF to block requests containing malicious scripts in device headers

Disable Plugin

linux

Temporarily disable POST SMTP Mailer plugin until patched

wp plugin deactivate post-smtp

🧯 If You Can't Patch

Implement strict Content Security Policy (CSP) headers to limit script execution
Deploy web application firewall with XSS protection rules

🔍 How to Verify

Check if Vulnerable:

Check WordPress admin → Plugins → Installed Plugins for POST SMTP Mailer version. If version is 2.8.7 or lower, you are vulnerable.

Check Version:

wp plugin get post-smtp --field=version

Verify Fix Applied:

Verify plugin version is 2.8.8 or higher in WordPress admin panel.

📡 Detection & Monitoring

Log Indicators:

HTTP requests with suspicious device headers containing script tags
Unusual POST requests to WordPress REST API endpoints

Network Indicators:

HTTP requests with device headers containing JavaScript code
Traffic to WordPress mobile API endpoints with malicious payloads

SIEM Query:

source="web_server" AND (uri_path="*wp-json*" OR uri_path="*mobile*" OR uri_path="*api*") AND http_header="device:*<script>*"

📊 Metadata

CVE ID: CVE-2023-7027

CVSS v3 Score: 7.2 (HIGH)

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

CWE: CWE-79

Published: January 3, 2024

Last Updated: November 21, 2024

🔗 References

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🔗 Related Vulnerabilities

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