CVE-2021-26828 — AI Deep Analysis Summary

🚨 **Essence**: ScadaBR allows **Remote Code Execution (RCE)** via file upload. 💥 **Consequences**: Attackers can upload arbitrary JSP files and execute commands on the server, leading to full system compromise.

🛡️ **Root Cause**: Lack of effective **permission licensing** and **access control**. 🐛 **Flaw**: Inadequate validation when handling file uploads via `view_edit.shtm`, allowing malicious code injection.

📦 **Affected**: Sensorweb ScadaBR. 📅 **Versions**: 0.9.1 (Linux) and through 1.0 / 1.12.4CE (Windows). ⚠️ **Note**: Older versions are primarily at risk.

🕵️ **Privileges**: Remote authenticated users. 📂 **Data/Action**: Can upload `.jsp` shells and execute **arbitrary code**. This grants full control over the underlying OS (Linux/Windows).

🔓 **Threshold**: Medium. 🆔 **Auth Required**: Yes, attackers need **valid credentials** (User/Pass) to access the upload interface. It is not fully unauthenticated.

🔥 **Exploitation**: High. 📜 **Public PoCs**: Multiple scripts available (e.g., `WinScada_RCE.py`, `LinScada_RCE.py`, `ScadaFlare`). 🌐 **Active**: Exploits are widely shared on GitHub.

🔍 **Self-Check**: Scan for ScadaBR instances. 🧪 **Test**: Use provided POC scripts with valid credentials to attempt JSP upload via `view_edit.shtm`. 📡 **Monitor**: Look for unauthorized JSP file uploads in logs.

🩹 **Fix**: Upgrade to a patched version > 1.12.4CE. 📝 **Official**: The vendor (Sensorweb) has acknowledged the issue; check their official forum or release notes for the specific patch.

🚧 **Workaround**: If patching is impossible, **restrict network access** to the ScadaBR interface. 🔒 **Mitigate**: Enforce strong **MFA** and limit user privileges to prevent unauthorized upload access.

⚡ **Urgency**: High. 🚨 **Priority**: Critical for SCADA environments. Even though auth is required, the impact (RCE) is severe. Patch immediately or isolate the system.