CVE Alert: CVE-2025-9812 – Tenda – CH22

Risk verdict

High-severity remote buffer overflow in Tenda CH22 presents active risk with publicly disclosed exploit; treat as priority 1.

Why this matters

Exploitation yields arbitrary code execution with system-level impact and no user interaction, potentially compromising the device and enabling movement within internal networks. Given CH22’s role as a gateway device, compromise could disrupt connectivity, expose targeted networks, or enable broader asset access.

Most likely attack path

Attack from the internet against the /goform/exeCommand interface using crafted cmdinput to trigger overflow. No user interaction required, and low privileges are sufficient, with the attacker gaining full control and high impact on confidentiality, integrity, and availability. Lateral movement would depend on the device’s role and network exposure, often followed by attempts to pivot to adjacent hosts or data flows.

Who is most exposed

Consumer and SMB deployments with WAN-facing remote management enabled are most at risk; devices commonly sit at the network edge and may be reachable from the internet or via misconfigured port forwarding.

Detection ideas

• Watch for repeated attempts to access /goform/exeCommand from outside the trusted network.
• Detect anomaly cmdinput lengths or payload patterns consistent with buffer overflow attempts.
• Look for device crashes, memory faults, or unusual reboot events in admin logs.
• Correlate with known IOCs or CTI indicators for this vulnerability.
• Alert on unusual admin activity from external IPs.

Mitigation and prioritisation

• Patch to latest firmware; treat as priority 1 if KEV/public exploit is confirmed.
• If patching isn’t possible, disable or restrict remote management to trusted networks or via VPN; apply strict WAN access controls.
• Review exposure: remove unnecessary port forwards, segment affected devices, and enforce least privilege for admin interfaces.
• Validate configurations and enable logging/monitoring of admin access and device crashes.
• Establish a rapid change-management plan for firmware upgrades and rollback testing.