Horizon Alert
Summary of the vulnerability and why it matters
This advisory concerns a critical vulnerability in Tenda AC6 wireless router firmware that could allow unauthorized remote access and control. The flaw, identified in the `formSetCfm` function, can be exploited without any prior authentication, posing a significant risk to the security and integrity of connected networks. Given the nature of the affected device and the ease of exploitation, confirming its relevance and exposure is the primary concern.
- Unauthenticated remote control vulnerability.
- Affects widely deployed consumer routers.
- Confirm relevance and exposure.
Attack Path
How an attacker could exploit the issue
An attacker could reach a vulnerable function within the Tenda AC6 router's firmware without any special access. By sending specially crafted requests to the router, an attacker could trigger a buffer overflow. If successful, this could allow an attacker to gain significant control over the device, potentially impacting its confidentiality, integrity, and availability.
- No authentication required.
- Specially crafted network requests.
- Full device compromise risk.
Live Threat
Current exploitation, exposure, and threat context
The Tenda AC6 router, when running firmware version 15.03.05.16_multi, contains a buffer overflow vulnerability in its `formSetCfm` function. This vulnerability can be exploited by an unauthenticated attacker over the network by sending specially crafted requests containing overly long values for the `funcname`, `funcpara1`, and `funcpara2` parameters. Such an attack could lead to a denial of service or potentially allow for arbitrary code execution, affecting the router's availability and security.
- Router firmware and its services.
- Network requests can trigger overflow.
- Denial of service or code execution.
Operational Fix
Recommended remediation, mitigation, and detection steps
This vulnerability in Tenda AC6 firmware likely impacts consumers and small businesses using these devices, especially if remote management is enabled. The first practical move is to identify all instances of this firmware, determine if they are exposed externally or to untrusted internal networks, and locate the individual or team accountable for managing these devices. Subsequently, a risk-based remediation plan, potentially involving vendor coordination or temporary mitigation, should be developed.
- Identify affected device owners.
- Verify external or critical exposure.
- Plan vendor-supported remediation.
