CVE-2022-36586 in Tenda
Summary
by MITRE • 09/08/2022
In Tenda G3 US_G3V3.0br_V15.11.0.6(7663)_EN_TDE, there is a buffer overflow vulnerability caused by strcpy in function 0x869f4 in the httpd binary.
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Analysis
by VulDB Data Team • 10/14/2022
The vulnerability identified as CVE-2022-36586 represents a critical buffer overflow flaw within the Tenda G3 router firmware version US_G3V3.0br_V15.11.0.6(7663)_EN_TDE. This issue resides in the httpd binary component which serves as the web server interface for the device's administrative console. The vulnerability manifests through the improper use of the strcpy function within a specific function located at memory address 0x869f4, creating an exploitable condition that could allow remote code execution or system compromise.
The technical implementation of this vulnerability stems from the insecure handling of user-supplied input through the httpd service. When the web server processes incoming HTTP requests containing crafted parameters, the strcpy function blindly copies data into a fixed-size buffer without proper bounds checking. This classic buffer overflow condition occurs because strcpy does not validate the source data length against the destination buffer capacity, allowing an attacker to overwrite adjacent memory locations. The vulnerability falls under CWE-121 which specifically addresses stack-based buffer overflow conditions, and it aligns with ATT&CK technique T1210 for exploiting weaknesses in remote services.
The operational impact of this vulnerability extends beyond simple denial of service scenarios. An attacker capable of exploiting this buffer overflow could potentially execute arbitrary code with the privileges of the httpd process, which typically runs with elevated permissions on the router. This could enable complete system compromise including unauthorized access to network traffic, modification of router configuration settings, installation of persistent backdoors, or redirection of network traffic through the compromised device. The remote nature of the exploit means that attackers do not require physical access to the device, making it particularly dangerous for network infrastructure components.
Mitigation strategies for this vulnerability should include immediate firmware updates from Tenda to address the buffer overflow condition through proper input validation and bounds checking. Network administrators should implement network segmentation and access controls to limit exposure of affected devices to untrusted networks. Additionally, monitoring for suspicious HTTP traffic patterns and implementing intrusion detection systems can help identify potential exploitation attempts. The vulnerability demonstrates the importance of secure coding practices including the use of safer string handling functions like strncpy or strlcpy instead of strcpy, along with comprehensive input validation and bounds checking mechanisms. Organizations should also consider implementing network access control lists and restricting administrative access to only necessary trusted networks to reduce the attack surface for such remote exploitation opportunities.