CVE-2024-42948 in FH1201
Summary
by MITRE • 08/15/2024
Tenda FH1201 v1.2.0.14 (408) was discovered to contain a stack overflow via the delno parameter in the fromPptpUserSetting 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 • 09/03/2024
The vulnerability identified as CVE-2024-42948 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 fromPptpUserSetting function which processes user input through the delno parameter, creating a pathway for malicious actors to exploit memory corruption vulnerabilities. The issue stems from inadequate input validation and bounds checking within the firmware's web server component, specifically when handling POST requests containing crafted delno values. The vulnerability manifests as a stack buffer overflow that can be triggered through network-based attacks without requiring authentication or physical access to the device. According to CWE standards, this represents a classic stack overflow vulnerability classified under CWE-121, which occurs when a program writes data beyond the boundaries of a fixed-length stack buffer. The attack vector leverages the web management interface of the router, making it accessible to remote threat actors who can craft malicious POST requests to exploit this weakness.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it creates potential for more severe consequences including system instability, reboot loops, and in some cases, arbitrary code execution depending on the specific memory layout and exploitation techniques employed. The DoS condition effectively renders the router inaccessible to legitimate users and network administrators, disrupting network connectivity for all devices relying on the affected router for internet access. From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1499.004 which involves network disruption through denial of service attacks. The vulnerability affects the availability aspect of the CIA triad, specifically targeting the router's ability to maintain continuous network services. Network administrators may experience significant downtime while investigating and resolving the issue, particularly in environments where multiple routers are deployed and managed centrally. The vulnerability's exploitation requires minimal technical expertise, making it attractive to threat actors seeking to disrupt network services at scale.
Mitigation strategies for CVE-2024-42948 should prioritize immediate firmware updates from Tenda's official support channels, as this represents the most effective defense against exploitation. Network segmentation and firewall rules can provide temporary protection by blocking unauthorized access to the router's web management interface, though this approach does not address the underlying vulnerability. Implementing network monitoring solutions that can detect unusual POST request patterns or malformed data packets may help identify exploitation attempts. Security teams should also consider disabling unnecessary services such as PPTP user settings functionality if not required for operations, reducing the attack surface. The vulnerability highlights the importance of secure coding practices including input validation, buffer length checking, and proper memory management in embedded systems. Organizations should conduct thorough vulnerability assessments of their network infrastructure to identify similar issues in other router models or firmware versions, as this type of stack overflow vulnerability is common in embedded networking equipment. Regular security audits and penetration testing of network devices can help identify and remediate such vulnerabilities before they can be exploited by malicious actors in the wild.