CVE-2021-4443 — AI Deep Analysis Summary

Q: What is this vulnerability? (Essence + Consequences)

🚨 **Essence**: Arbitrary File Creation via QuadMenu plugin. 💥 **Consequences**: Full system compromise. CVSS 9.1 (Critical). Total loss of Confidentiality, Integrity, and Availability.

Q: Root Cause? (CWE/Flaw)

🛡️ **Root Cause**: CWE-434 (Unrestricted Upload of File with Dangerous Type). 🔍 **Flaw**: Insecure handling of file uploads allows attackers to write arbitrary files to the server.

Q: Who is affected? (Versions/Components)

📦 **Affected**: WordPress Plugin: **QuadMenu – Mega Menu**. 📅 **Version**: v2.0.6 and earlier. 🏢 **Vendor**: Quadlayers.

Q: What can hackers do? (Privileges/Data)

💀 **Attacker Actions**: Create arbitrary files. 🔓 **Privileges**: Remote Code Execution (RCE). 📊 **Impact**: Complete control over the WordPress environment. No authentication required.

Q: Is exploitation threshold high? (Auth/Config)

⚡ **Threshold**: **LOW**. 🌐 **Access**: Network (AV:N). 🔑 **Auth**: None required (PR:N). 👀 **UI**: None required (UI:N). Easy to exploit remotely.

Q: Is there a public Exp? (PoC/Wild Exploitation)

📢 **Public Exp?**: Yes. 🔗 **Sources**: Acunetix, Wordfence, and Sh3llcon reports confirm RCE capabilities. ⚠️ **Status**: Wild exploitation potential exists.

Q: How to self-check? (Features/Scanning)

🔍 **Self-Check**: Scan for **QuadMenu** plugin. 📋 **Version Check**: Verify if version ≤ 2.0.6. 🛠️ **Tools**: Use WPScan or Acunetix to detect the specific vulnerability signature.

Q: Is it fixed officially? (Patch/Mitigation)

✅ **Fix**: **Yes**. 🔄 **Action**: Update QuadMenu to the latest version immediately. 📝 **Note**: The vulnerability was disclosed in Oct 2024; patches should be available.

Q: Is it urgent? (Priority Suggestion)

🔥 **Urgency**: **CRITICAL**. 🚀 **Priority**: Patch immediately. ⏱️ **Reason**: CVSS 9.1 + No Auth + RCE = High risk of immediate compromise. Do not delay.

Updated May 08, 2026 CVSS 9.8 · Critical

This is a summary of the AI-generated 10-question deep analysis. The full version (longer answers, follow-up Q&A, related CVEs) requires login. Read the full analysis →

Q1What is this vulnerability? (Essence + Consequences)

🚨 **Essence**: Arbitrary File Creation via QuadMenu plugin. <br>💥 **Consequences**: Full system compromise. CVSS 9.1 (Critical). Total loss of Confidentiality, Integrity, and Availability.

Q2Root Cause? (CWE/Flaw)

🛡️ **Root Cause**: CWE-434 (Unrestricted Upload of File with Dangerous Type). <br>🔍 **Flaw**: Insecure handling of file uploads allows attackers to write arbitrary files to the server.

Q3Who is affected? (Versions/Components)

📦 **Affected**: WordPress Plugin: **QuadMenu – Mega Menu**. <br>📅 **Version**: v2.0.6 and earlier. <br>🏢 **Vendor**: Quadlayers.

Q4What can hackers do? (Privileges/Data)

💀 **Attacker Actions**: Create arbitrary files. <br>🔓 **Privileges**: Remote Code Execution (RCE). <br>📊 **Impact**: Complete control over the WordPress environment. No authentication required.

Q5Is exploitation threshold high? (Auth/Config)

⚡ **Threshold**: **LOW**. <br>🌐 **Access**: Network (AV:N). <br>🔑 **Auth**: None required (PR:N). <br>👀 **UI**: None required (UI:N). Easy to exploit remotely.

Q6Is there a public Exp? (PoC/Wild Exploitation)

📢 **Public Exp?**: Yes. <br>🔗 **Sources**: Acunetix, Wordfence, and Sh3llcon reports confirm RCE capabilities. <br>⚠️ **Status**: Wild exploitation potential exists.

Q7How to self-check? (Features/Scanning)

🔍 **Self-Check**: Scan for **QuadMenu** plugin. <br>📋 **Version Check**: Verify if version ≤ 2.0.6. <br>🛠️ **Tools**: Use WPScan or Acunetix to detect the specific vulnerability signature.

Q8Is it fixed officially? (Patch/Mitigation)

✅ **Fix**: **Yes**. <br>🔄 **Action**: Update QuadMenu to the latest version immediately. <br>📝 **Note**: The vulnerability was disclosed in Oct 2024; patches should be available.

Q9What if no patch? (Workaround)

🚧 **No Patch?**: Disable the plugin immediately. <br>🧹 **Cleanup**: Remove QuadMenu if not essential. <br>🛡️ **WAF**: Block upload endpoints if possible.…

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Q10Is it urgent? (Priority Suggestion)

🔥 **Urgency**: **CRITICAL**. <br>🚀 **Priority**: Patch immediately. <br>⏱️ **Reason**: CVSS 9.1 + No Auth + RCE = High risk of immediate compromise. Do not delay.

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Vulnerability detail Full AI analysis (login) quadlayers CWE-434