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 β
Q1What is this vulnerability? (Essence + Consequences)
π¨ **Essence**: A stack buffer overflow in Tenda AC11 routers. π **Consequences**: Attackers can execute arbitrary code on the device via a crafted POST request to `/goform/setmac`. Total device compromise is possible.
Q2Root Cause? (CWE/Flaw)
π οΈ **Root Cause**: Stack Buffer Overflow. π₯ **Flaw**: The `/goform/setmac` endpoint fails to properly validate input length, allowing malicious data to overflow the buffer and hijack execution flow.
Q3Who is affected? (Versions/Components)
π± **Device**: Tenda AC11 Router. π¦ **Affected Versions**: Firmware version **02.03.01.104_CN** and all earlier versions. β οΈ If you have this router, you are at risk.
Q4What can hackers do? (Privileges/Data)
π» **Privileges**: Arbitrary Code Execution (RCE). π΅οΈ **Impact**: Hackers gain full control over the router. They can run commands, steal network data, or use the device as a botnet node. No user interaction needed.
Q5Is exploitation threshold high? (Auth/Config)
π **Auth Status**: Unauthenticated. π **Threshold**: LOW. Attackers do NOT need to log in. A simple remote POST request is enough to trigger the vulnerability. Extremely easy to exploit.
Q6Is there a public Exp? (PoC/Wild Exploitation)
π₯ **Exploit Availability**: YES. Public POCs exist on GitHub (e.g., `r3s3tt/CVE-2021-31755`). π§ͺ Tools like Nuclei also have templates. Wild exploitation is highly likely given the ease of access.
Q7How to self-check? (Features/Scanning)
π **Self-Check**: Scan for Tenda AC11 devices. π‘ Check if firmware is <= 02.03.01.104_CN. π οΈ Use Nuclei templates or custom scripts targeting the `/goform/setmac` endpoint to verify susceptibility.
Q8Is it fixed officially? (Patch/Mitigation)
π‘οΈ **Fix**: Update firmware to the latest version provided by Tenda. π₯ **Action**: Check Tenda's official support page for AC11. Install the patch immediately to close the buffer overflow gap.
Q9What if no patch? (Workaround)
π§ **No Patch?**: Block external access to the router's web management interface. π« **Mitigation**: Disable remote management features. If possible, isolate the router in a segmented network to limit lateral movement.
Q10Is it urgent? (Priority Suggestion)
π΄ **Priority**: CRITICAL. β‘ **Urgency**: HIGH. Since it is unauthenticated and allows RCE, this is a top-priority vulnerability. Patch immediately or face potential compromise.