CVE-2024-42946 in FH1201
Summary
by MITRE • 08/15/2024
Tenda FH1201 v1.2.0.14 (408) was discovered to contain a stack overflow via the page parameter in the fromVirtualSer function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted POST request.
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Analysis
by VulDB Data Team • 08/17/2024
The vulnerability identified as CVE-2024-42946 affects the Tenda FH1201 router firmware version 1.2.0.14 (build 408) and represents a critical stack overflow condition within the web interface handling mechanism. This flaw exists in the fromVirtualSer function where the page parameter is processed without adequate input validation or bounds checking. The vulnerability manifests when a malicious actor submits a crafted POST request containing an oversized or malformed page parameter value that exceeds the allocated stack buffer space. The stack overflow condition occurs during the processing of user-supplied input, specifically within the web server component responsible for handling administrative interface requests.
The technical exploitation of this vulnerability follows a classic stack buffer overflow attack pattern where insufficient boundary checks allow an attacker to overwrite adjacent memory locations on the stack. This particular implementation flaw demonstrates poor input sanitization practices and violates fundamental secure coding principles that are commonly referenced in CWE-121, which addresses stack-based buffer overflow conditions. The vulnerability's impact is primarily focused on Denial of Service conditions where the router's web interface becomes unresponsive or crashes entirely, rendering the device inaccessible to legitimate users. The attack vector requires only a simple POST request with a specially crafted payload, making it particularly dangerous as it can be exploited remotely without authentication.
From an operational perspective, this vulnerability compromises the availability and integrity of the affected network infrastructure by potentially rendering the router's management interface unusable. The DoS condition affects not only the administrative access but also impacts the router's ability to function normally as a network gateway, potentially causing network outages for all devices relying on the affected router for connectivity. This vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and represents a significant risk to enterprise and home network security. The vulnerability's exploitation does not require advanced privileges or specialized tools, making it accessible to threat actors with basic web application attack knowledge.
Security mitigations for this vulnerability should include immediate firmware updates from Tenda to address the buffer overflow condition in the web interface handling code. Network administrators should implement network segmentation to limit access to administrative interfaces and deploy intrusion detection systems to monitor for suspicious POST requests containing oversized parameters. The vulnerability highlights the importance of input validation and proper memory management in embedded systems, particularly those handling network traffic and administrative functions. Organizations should also consider implementing web application firewalls to filter malicious requests and regularly audit their network infrastructure for similar buffer overflow conditions. The flaw demonstrates the critical need for secure coding practices and thorough security testing of embedded firmware components before deployment in production environments.