CVE-2023-43885 in RX9 Pro
Summary
by MITRE • 11/07/2023
Missing error handling in the HTTP server component of Tenda RX9 Pro Firmware V22.03.02.20 allows authenticated attackers to arbitrarily lock the device.
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Analysis
by VulDB Data Team • 02/08/2026
The vulnerability identified as CVE-2023-43885 represents a critical security flaw within the Tenda RX9 Pro wireless router firmware version 22.03.02.20. This issue stems from inadequate error handling mechanisms within the HTTP server component that governs the device's web-based administration interface. The flaw specifically affects authenticated users who possess valid login credentials, making it particularly concerning as it requires minimal privileges to exploit. The vulnerability manifests as a privilege escalation condition where an attacker can manipulate the device's operational state to achieve arbitrary locking, effectively rendering the device inaccessible to legitimate users. This type of vulnerability falls under the CWE-707 category of improper use of tainted data, specifically involving the failure to properly validate and handle error conditions during HTTP request processing. The attack vector leverages the existing authentication mechanism to gain access to administrative functions, which then allows for the manipulation of device locking states through crafted requests that bypass normal operational safeguards.
The technical implementation of this vulnerability occurs within the HTTP server module's request handling pipeline where specific error conditions are not properly managed or caught during processing of administrative commands. When an authenticated user submits certain malformed or specially crafted requests through the web interface, the server fails to properly validate the inputs or handle the resulting error states. This lack of robust error handling creates a condition where the system enters an unexpected state that ultimately results in the device becoming locked or unresponsive. The vulnerability demonstrates poor defensive programming practices where error conditions that should trigger graceful degradation or user feedback instead cause the system to enter a locked state. From an operational perspective, this issue directly impacts the device's availability and maintainability, as legitimate administrators lose access to the device's management interface and must resort to physical intervention or firmware recovery procedures to regain control. The flaw also represents a potential denial-of-service condition that could be exploited by malicious actors to disrupt network services or gain unauthorized access to the device's operational state.
The operational impact of CVE-2023-43885 extends beyond simple device locking to encompass broader security implications for network infrastructure management. Network administrators who rely on remote access to configure and monitor their Tenda RX9 Pro devices face significant operational challenges when this vulnerability is exploited, as it effectively removes their ability to manage the device through standard administrative channels. This vulnerability aligns with ATT&CK technique T1210: Exploitation of Remote Services, as it exploits the device's web-based management interface to achieve unauthorized access to system controls. The attack requires minimal sophistication beyond having valid authentication credentials, making it particularly dangerous in environments where device credentials might be compromised through social engineering, credential theft, or other means. Organizations using affected firmware versions must consider this vulnerability as a potential entry point for more extensive attacks, as device locking could be used as a precursor to other malicious activities or as a means of creating persistent access points. The vulnerability also highlights the importance of proper error handling in embedded systems and web applications, particularly in network infrastructure devices where availability is paramount to operational continuity.
Mitigation strategies for CVE-2023-43885 should prioritize immediate firmware updates from Tenda to address the root cause of the error handling deficiency. Network administrators should implement strict access controls and monitoring of administrative interfaces to detect anomalous behavior that might indicate exploitation attempts. The vulnerability demonstrates the critical need for proper input validation and error handling in all network services, particularly those with administrative privileges. Organizations should establish procedures for rapid response to such vulnerabilities, including automated patch deployment mechanisms and network segmentation to limit potential impact. Additionally, implementing network-based intrusion detection systems can help identify exploitation attempts by monitoring for unusual patterns in administrative traffic. The vulnerability also underscores the importance of secure coding practices and adherence to security standards such as the OWASP Top 10, specifically addressing the prevention of error handling vulnerabilities that could lead to system instability or unauthorized access. Regular security audits of network infrastructure components should include assessment of error handling mechanisms to prevent similar issues from emerging in other firmware components or third-party applications.