CVE-2024-6964 in Tenda
Summary
by MITRE • 07/22/2024
A vulnerability, which was classified as critical, was found in Tenda O3 1.0.0.10. Affected is the function fromDhcpSetSer. The manipulation of the argument dhcpEn/startIP/endIP/preDNS/altDNS/mask/gateway leads to stack-based buffer overflow. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. VDB-272118 is the identifier assigned to this vulnerability. NOTE: The vendor was contacted early about this disclosure but did not respond in any way.
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Analysis
by VulDB Data Team • 07/26/2024
The vulnerability identified as CVE-2024-6964 represents a critical stack-based buffer overflow flaw in the Tenda O3 router firmware version 1.0.0.10. This vulnerability specifically affects the fromDhcpSetSer function, which handles DHCP server configuration parameters within the device's network management interface. The flaw arises from inadequate input validation when processing DHCP configuration arguments including dhcpEn, startIP, endIP, preDNS, altDNS, mask, and gateway parameters. The absence of proper bounds checking allows malicious actors to overflow the allocated stack buffer, potentially leading to arbitrary code execution or system compromise. This vulnerability is particularly concerning as it enables remote exploitation without requiring local access or authentication credentials, making it accessible to attackers anywhere on the network.
The technical implementation of this buffer overflow vulnerability stems from the function's failure to properly validate the length of input data provided in DHCP configuration parameters. When an attacker sends specially crafted requests containing excessively long strings in any of the affected parameters, the function fails to enforce size limits, causing data to overwrite adjacent memory locations on the stack. This type of vulnerability maps directly to CWE-121 Stack-based Buffer Overflow, which is classified as a critical weakness in the Common Weakness Enumeration catalog. The overflow can potentially overwrite return addresses, function pointers, or other critical stack variables, enabling attackers to redirect program execution flow or inject malicious code into the router's memory space.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to encompass full system compromise and potential network infiltration. Remote exploitation allows attackers to execute arbitrary code with the privileges of the affected service, which typically runs with elevated permissions on the router. This could enable attackers to modify network configurations, redirect traffic through malicious servers, establish persistent backdoors, or use the compromised device as a launching point for attacks against other networked systems. The vulnerability's classification as critical by security vendors reflects the potential for widespread impact, as routers serve as fundamental network infrastructure components that often remain unpatched for extended periods. Network administrators may be unaware of compromised devices until significant damage has occurred, particularly in environments where default credentials remain unchanged or where network monitoring is insufficient.
Mitigation strategies for CVE-2024-6964 should prioritize immediate action to address the vulnerability through firmware updates provided by Tenda, although the vendor's lack of response to early disclosure concerns raises additional security implications. Organizations should implement network segmentation to isolate affected devices from critical infrastructure and establish monitoring for unusual network traffic patterns that might indicate exploitation attempts. Network administrators should consider disabling unnecessary services and implementing strict access controls for router management interfaces. The vulnerability demonstrates the importance of proper input validation and bounds checking in network device firmware development, aligning with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1566.001 for Phishing as attackers could potentially use the compromised device to launch further network attacks. Additionally, this vulnerability highlights the need for robust firmware security practices including regular security assessments, proper code review processes, and adherence to secure coding standards to prevent similar flaws in future device implementations.