CVE-2025-9443 in CH22
Summary
by MITRE • 08/26/2025
A flaw has been found in Tenda CH22 1.0.0.1. This vulnerability affects the function formeditUserName of the file /goform/editUserName. Executing manipulation of the argument new_account can lead to buffer overflow. It is possible to launch the attack remotely. The exploit has been published and may be used.
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Analysis
by VulDB Data Team • 08/26/2025
The vulnerability identified as CVE-2025-9443 represents a critical buffer overflow flaw within the Tenda CH22 router firmware version 1.0.0.1. This issue resides in the web-based management interface, specifically within the formeditUserName function located at /goform/editUserName endpoint. The vulnerability stems from inadequate input validation and bounds checking when processing the new_account parameter, creating an exploitable condition that allows attackers to manipulate the argument in ways that exceed allocated buffer space. The affected device operates with a web server that processes HTTP requests through the goform framework, which handles form submissions for various administrative functions including user account management.
The technical implementation of this vulnerability demonstrates a classic buffer overflow condition classified under CWE-121, where insufficient bounds checking allows memory corruption through excessive data input. When an attacker submits a specially crafted payload to the new_account parameter, the application fails to properly validate the length of the input data against the allocated buffer size, enabling the overflow to occur. This condition can be exploited remotely through the web interface, eliminating the need for physical access or local network presence. The vulnerability's remote exploitability is particularly concerning as it allows adversaries to execute arbitrary code on the device without authentication, potentially leading to complete system compromise and unauthorized access to the network infrastructure.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with the capability to gain persistent access to network infrastructure through the compromised router. The Tenda CH22 device serves as a critical network gateway, and its compromise can lead to man-in-the-middle attacks, DNS hijacking, traffic interception, and unauthorized network access. According to ATT&CK framework categorization, this vulnerability maps to T1071.001 Application Layer Protocol: Web Protocols, T1059.007 Command and Scripting Interpreter: JavaScript, and T1566.001 Impairing Defenses: Disable or Modify Tools. The exploit's publication increases the risk profile significantly as it removes the requirement for advanced exploitation techniques and allows less sophisticated attackers to leverage the vulnerability effectively.
Mitigation strategies for CVE-2025-9443 must include immediate firmware updates from Tenda, as the vendor should release patches addressing the input validation flaws in the web interface. Network administrators should implement strict firewall rules to restrict access to the router's web management interface from untrusted networks, and consider disabling web management entirely if not required for administrative purposes. Additionally, implementing network segmentation and monitoring for unusual traffic patterns can help detect exploitation attempts. The vulnerability highlights the importance of secure coding practices and input validation, particularly for embedded devices that serve as network gateways. Organizations should conduct comprehensive vulnerability assessments of their network infrastructure to identify similar issues in other router models and firmware versions, as this represents a common pattern in embedded device security flaws that require immediate attention to prevent widespread compromise of network infrastructure.