CVE-2021-25070 – This SQL injection vulnerability in the Block B... (How to Fix)

Q: What is the severity of CVE-2021-25070?

CVE-2021-25070 has a CVSS score of 9.8 (CRITICAL). This SQL injection vulnerability in the Block Bad Bots WordPress plugin allows attackers to execute arbitrary SQL commands by manipulating the User-Agent header. WordPress sites using vulnerable versions of this plugin are affected, potentially compromising the underlying database.

📋 TL;DR

This SQL injection vulnerability in the Block Bad Bots WordPress plugin allows attackers to execute arbitrary SQL commands by manipulating the User-Agent header. WordPress sites using vulnerable versions of this plugin are affected, potentially compromising the underlying database.

💻 Affected Systems

Products:

Block Bad Bots WordPress plugin

Versions: All versions before 6.88

Operating Systems: All

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects WordPress installations with the vulnerable plugin enabled.

📦 What is this software?

Block And Stop Bad Bots by Stopbadbots

View all CVEs affecting Block And Stop Bad Bots →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete database compromise allowing data theft, modification, or deletion, and potential remote code execution via database functions.

🟠

Likely Case

Data exfiltration from the WordPress database including user credentials, sensitive content, and plugin data.

🟢

If Mitigated

Limited impact with proper input validation and database permissions restricting damage to the plugin's own tables.

🌐 Internet-Facing: HIGH

🏢 Internal Only: LOW

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploitation requires sending HTTP requests with malicious User-Agent strings to the WordPress site.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 6.88

Vendor Advisory: https://wpscan.com/vulnerability/e00b2946-15e5-4458-9b13-2e272630a36f

Restart Required: No

Instructions:

1. Log into WordPress admin panel. 2. Navigate to Plugins > Installed Plugins. 3. Find 'Block Bad Bots' and update to version 6.88 or later. 4. Verify update completed successfully.

🔧 Temporary Workarounds

Disable Plugin

all

Temporarily disable the vulnerable plugin until patching is possible.

wp plugin deactivate block-bad-bots

WAF Rule

all

Implement web application firewall rules to block SQL injection patterns in User-Agent headers.

🧯 If You Can't Patch

Implement strict input validation for User-Agent headers at the web server level.
Restrict database user permissions to minimize potential damage from SQL injection.

🔍 How to Verify

Check if Vulnerable:

Check WordPress admin panel for plugin version, or examine wp-content/plugins/block-bad-bots/block-bad-bots.php file version header.

Check Version:

wp plugin get block-bad-bots --field=version

Verify Fix Applied:

Confirm plugin version is 6.88 or higher in WordPress admin or via file inspection.

📡 Detection & Monitoring

Log Indicators:

Unusual SQL errors in WordPress logs
Suspicious User-Agent strings containing SQL keywords

Network Indicators:

HTTP requests with SQL injection patterns in User-Agent header

SIEM Query:

SELECT * FROM web_logs WHERE user_agent LIKE '%UNION%' OR user_agent LIKE '%SELECT%' OR user_agent LIKE '%INSERT%'

📊 Metadata

CVE ID: CVE-2021-25070

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-89

Published: March 28, 2022

Last Updated: November 21, 2024

🔗 References

https://wpscan.com/vulnerability/e00b2946-15e5-4458-9b13-2e272630a36f Exploit,Third Party Advisory
https://wpscan.com/vulnerability/e00b2946-15e5-4458-9b13-2e272630a36f Exploit,Third Party Advisory

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2021-25070, you might also want to check these: