CVE-2019-5591 — AI Deep Analysis Summary

🚨 **Essence**: A Man-In-The-Middle (MITM) flaw in FortiOS LDAP config. 📉 **Consequences**: Attackers can impersonate LDAP servers to steal sensitive credentials and user data from the local subnet.…

🛡️ **Root Cause**: Missing **Server Identity Check** for LDAP/S. 🔍 **Flaw**: The system does not validate the CA certificate or server identity.…

🏢 **Vendor**: Fortinet. 📦 **Product**: Fortinet FortiOS. 📅 **Affected Versions**: **6.0.3 through 6.2.0** (including 6.2.0 and earlier). ✅ **Safe**: Version 7.0 is NOT affected. ⚠️ **Fix**: Upgrade to **6.2.1 or above**.

💻 **Hackers Can**: Perform MITM attacks on the local subnet. 🔑 **Data Stolen**: Full exfiltration of **LDAP credentials** (usernames/passwords) sent to the LDAP server.…

⚖️ **Threshold**: **Medium/Low**. 🌐 **Config**: Depends on **default LDAP configuration** lacking identity checks. 📡 **Network**: Requires access to the **local subnet** where the FortiGate resides.…

🔓 **Public Exp?**: **YES**. 📂 **PoC Available**: GitHub repo `ayewo/fortios-ldap-mitm-poc-CVE-2019-5591` demonstrates full credential exfiltration. 🧪 **Detection**: Nuclei templates exist for automated scanning.…

🔍 **Self-Check**: Scan for **missing CA-cert**, **insecure LDAPS**, or **disabled server-identity-check** in LDAP config.…

🛠️ **Official Fix**: **YES**. 📥 **Action**: Upgrade FortiOS to version **6.2.1 or higher**. 🚫 **Old Versions**: 6.0.3–6.2.0 remain vulnerable. 🔄 **Status**: Patch released via PSIRT FG-IR-19-037.

🚧 **No Patch Workaround**: Enable **Server Identity Check** in LDAP settings. 🔒 **Enforce**: Use valid **CA certificates** for LDAPS. 🚫 **Restrict**: Limit LDAP traffic to trusted networks only.…

🔥 **Urgency**: **HIGH**. 🚨 **Why**: Easy MITM attack, credential theft, default config vulnerable. 📅 **Published**: Aug 2020 (still relevant for unpatched systems).…