CVE-2024-42949 in FH1201
Summary
by MITRE • 08/15/2024
Tenda FH1201 v1.2.0.14 (408) was discovered to contain a stack overflow via the qos parameter in the fromqossetting 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-2024-42949 affects the Tenda FH1201 router firmware version 1.2.0.14 build 408, representing a critical stack overflow condition within the device's web interface handling mechanism. This flaw exists in the fromqossetting function where the qos parameter is processed without adequate input validation or bounds checking, creating an exploitable condition that can be leveraged by remote attackers to disrupt service availability.
The technical implementation of this vulnerability stems from improper memory management practices within the router's embedded web server component. When a malicious actor submits a crafted POST request containing an oversized qos parameter value, the application fails to validate the input length before copying it to a fixed-size stack buffer. This classic stack buffer overflow scenario occurs because the firmware does not implement proper bounds checking or input sanitization routines before processing user-supplied data, allowing the overflow to overwrite adjacent stack memory locations including return addresses and control data.
From an operational perspective, this vulnerability presents a significant risk to network availability and system stability. The Denial of Service condition can be triggered remotely without authentication requirements, making it particularly dangerous for network administrators who may not immediately detect the compromise. The attack vector requires only a single crafted POST request to the affected router's web interface, making exploitation straightforward and potentially automated. Network infrastructure devices running this vulnerable firmware become susceptible to immediate service disruption, potentially affecting all connected devices and network operations.
The vulnerability maps directly to CWE-121 Stack-based Buffer Overflow, which is classified under the Common Weakness Enumeration framework as a fundamental memory safety issue. This weakness category is particularly concerning in embedded systems and network appliances where robustness and reliability are paramount. The ATT&CK framework categorizes this vulnerability under T1499.004 Network Denial of Service, highlighting the malicious use of network infrastructure to disrupt services. Additionally, the vulnerability demonstrates characteristics of T1595.001 Reconnaissance using network scanning techniques that could be employed to identify affected devices within network ranges.
Mitigation strategies for this vulnerability should begin with immediate firmware updates from Tenda, as the manufacturer has likely released patched versions addressing the buffer overflow condition. Network administrators should implement network segmentation and access control measures to limit exposure, particularly by restricting direct internet access to administrative interfaces. Additional protective measures include deploying intrusion detection systems capable of identifying suspicious POST requests containing oversized parameters and implementing web application firewalls to filter malicious traffic. Regular vulnerability assessments and network scanning should be conducted to identify other potentially affected devices within the network infrastructure. The long-term solution requires comprehensive input validation and memory safety practices in embedded firmware development, including the adoption of safe string handling functions and runtime stack protection mechanisms such as stack canaries or address space layout randomization.