CVE-2021-31195 — AI Deep Analysis Summary

🚨 **Essence**: A **Code Injection** flaw in Microsoft Exchange Server. 📧 **Consequences**: Attackers can inject malicious code, potentially leading to **data breaches** or **system compromise**.…

🛡️ **Root Cause**: The provided data lists **CWE ID as null**. However, the PoC description reveals a **Cross-Site Scripting (XSS)** vulnerability in the `refurl` parameter of `frowny.asp`.…

🏢 **Affected Products**: Microsoft Exchange Server.…

💻 **Attacker Capabilities**: - **Privileges**: Requires **User Interaction** (UI:R). - **Data**: **High** impact on Confidentiality (C:H). - **Impact**: Can execute injected scripts/code.…

🔓 **Exploitation Threshold**: - **Network**: Remote (AV:N) 🌐 - **Complexity**: Low (AC:L) ⚡ - **Auth**: None required for vector (PR:N), BUT **User Interaction** is required (UI:R) 👤.…

💣 **Public Exploit**: **Yes**. A PoC is available via **Nuclei Templates** on GitHub. 🔗 Link: `projectdiscovery/nuclei-templates`. This means automated scanning tools can detect and potentially exploit this easily.

🔍 **Self-Check**: - Use **Nuclei** with the specific CVE template. - Check for the presence of `frowny.asp` and the `refurl` parameter. - Scan for XSS payloads in the `refurl` input field. 🕵️‍♂️

🩹 **Official Fix**: **Yes**. Microsoft published the advisory on **2021-05-11**. 📅 Organizations should apply the latest Cumulative Updates or security patches provided by Microsoft to resolve this.

🚧 **No Patch?**: - **Mitigation**: Block external access to `frowny.asp` via WAF rules. - **Filtering**: Sanitize the `refurl` parameter to prevent XSS injection.…

🔥 **Urgency**: **HIGH**. - **CVSS**: Remote, Low Complexity, High Impact. - **Availability**: Public PoC exists. - **Action**: Patch immediately! ⏳ Don't wait. Exchange is a critical infrastructure component.