CVE-2025-12235 Overview
CVE-2025-12235 is a buffer overflow vulnerability in the Tenda CH22 router running firmware version 1.0.0.1. The flaw resides in the fromSetIpBind function within the /goform/SetIpBind endpoint. An attacker on the adjacent network can manipulate the page argument to trigger memory corruption. The exploit has been publicly disclosed, increasing the likelihood of active abuse against exposed devices.
Critical Impact
Adjacent-network attackers with low privileges can corrupt memory in the router's HTTP handler, potentially achieving arbitrary code execution and full device compromise.
Affected Products
- Tenda CH22 router (hardware)
- Tenda CH22 firmware version 1.0.0.1
- Devices exposing the /goform/SetIpBind web management endpoint on the local network
Discovery Timeline
- 2025-10-27 - CVE-2025-12235 published to the National Vulnerability Database (NVD)
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-12235
Vulnerability Analysis
The vulnerability is a classic buffer overflow classified under [CWE-119] (Improper Restriction of Operations within the Bounds of a Memory Buffer) and [CWE-120] (Buffer Copy without Checking Size of Input). It affects the fromSetIpBind handler, which processes IP-to-MAC binding configuration requests through the router's web administration interface at /goform/SetIpBind.
The handler copies attacker-controlled data from the page HTTP parameter into a fixed-size stack or heap buffer without validating the input length. Oversized values overflow the destination buffer and overwrite adjacent memory, including saved return addresses on MIPS or ARM stack frames typical of Tenda embedded firmware.
Successful exploitation yields impact to confidentiality, integrity, and availability of the device. This aligns with the EPSS probability of 4.826% (91.3 percentile), indicating elevated real-world exploitation likelihood relative to the broader CVE population.
Root Cause
The root cause is missing bounds checking on the page request parameter before it is written into a bounded buffer inside fromSetIpBind. The routine assumes the web interface will only supply short, well-formed values, but the endpoint is reachable without such input sanitization.
Attack Vector
An attacker must have network access adjacent to the target router and low-privileged access to the web management interface. The attacker sends a crafted HTTP request to /goform/SetIpBind containing an oversized page parameter. No user interaction is required. Because the exploit is public, unauthenticated proximity attackers on guest Wi-Fi, corporate LANs, or malicious insiders can weaponize it directly.
See the GitHub CVE Issue Discussion and VulDB entry #329905 for technical details on the parameter and endpoint.
Detection Methods for CVE-2025-12235
Indicators of Compromise
- HTTP POST or GET requests to /goform/SetIpBind containing abnormally long page parameter values.
- Unexpected reboots, crashes, or httpd process restarts on the Tenda CH22 router.
- New or unexplained changes to IP-MAC binding configuration on the device.
- Outbound connections from the router to unfamiliar hosts, suggesting post-exploitation implant activity.
Detection Strategies
- Deploy network intrusion detection signatures that flag requests to /goform/SetIpBind with page parameter length exceeding expected bounds (for example, over 128 bytes).
- Inspect router syslog and web server logs for repeated malformed requests to goform endpoints.
- Baseline management-plane traffic and alert on management HTTP requests originating from non-administrative hosts.
Monitoring Recommendations
- Forward router logs to a centralized SIEM or data lake for correlation with endpoint and identity telemetry.
- Monitor for lateral movement or scanning activity originating from the router segment following suspected exploitation.
- Track firmware version inventory to identify Tenda CH22 devices still running 1.0.0.1.
How to Mitigate CVE-2025-12235
Immediate Actions Required
- Restrict access to the router's web management interface to trusted administrative hosts only using ACLs or a management VLAN.
- Disable remote management if enabled and change default administrative credentials.
- Segment the Tenda CH22 from user, guest, and IoT networks to limit adjacent-network exposure.
- Audit existing IP-MAC bindings and configuration for signs of unauthorized modification.
Patch Information
At the time of publication, no vendor advisory or firmware update addressing CVE-2025-12235 has been referenced in the NVD entry. Consult the Tenda official website for updated firmware releases and monitor VulDB #329905 for advisory updates.
Workarounds
- Block inbound access to /goform/SetIpBind at an upstream firewall where feasible.
- Place the router behind a management jump host and require VPN access for administrative operations.
- Replace the affected device with a supported model if a vendor patch is not made available in a timely manner.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
