CVE-2024-7174 in A3600R
Summary
by MITRE • 07/29/2024
A vulnerability, which was classified as critical, was found in TOTOLINK A3600R 4.1.2cu.5182_B20201102. This affects the function setdeviceName of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument deviceMac/deviceName leads to buffer overflow. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. The associated identifier of this vulnerability is VDB-272595. 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 • 08/06/2024
The vulnerability identified as CVE-2024-7174 represents a critical buffer overflow flaw in the TOTOLINK A3600R router firmware version 4.1.2cu.5182_B20201102. This vulnerability resides within the setdeviceName function of the /cgi-bin/cstecgi.cgi file, which serves as a critical component for device management and configuration within the router's web interface. The flaw manifests when processing the deviceMac and deviceName parameters, creating a condition where input validation is insufficient to prevent excessive data from being written to fixed-length buffers. This particular vulnerability is classified under CWE-121 as a stack-based buffer overflow, which occurs when more data is written to a buffer than it can accommodate, potentially overwriting adjacent memory locations. The attack vector is remotely exploitable, meaning that an unauthenticated attacker can trigger the vulnerability without requiring physical access or local network privileges. This remote exploitation capability significantly increases the threat surface and potential impact of the vulnerability. The vulnerability has been publicly disclosed and is actively being used in the wild, as indicated by the VDB-272595 identifier, which suggests that security researchers and malicious actors have already developed working exploits. The fact that the vendor was contacted early in the disclosure process without any response indicates a potential lack of coordinated vulnerability disclosure efforts, leaving users exposed to the risk of exploitation. The buffer overflow vulnerability in this context could potentially allow attackers to execute arbitrary code on the affected device, escalate privileges, or cause a denial of service condition that would render the router inoperable. The specific function setdeviceName is particularly concerning because it likely handles device identification and configuration parameters that are essential for network operations. When an attacker sends malformed deviceMac or deviceName parameters to the vulnerable cgi script, the insufficient input validation allows for buffer overflow conditions that could be leveraged to overwrite critical memory locations including return addresses, function pointers, or other control data structures. This vulnerability directly maps to techniques described in the MITRE ATT&CK framework under the T1059.007 sub-technique for command and scripting interpreter, where attackers can leverage buffer overflows to execute malicious code. The attack scenario involves an attacker sending specially crafted HTTP requests to the router's web interface, specifically targeting the vulnerable cgi endpoint with oversized parameters that will overflow the designated buffers. The lack of vendor response to the initial disclosure creates a dangerous precedent where users remain exposed to known vulnerabilities for extended periods, potentially allowing for the development of more sophisticated attack vectors or the integration of this vulnerability into broader exploit frameworks. This vulnerability impacts the integrity and availability of the network infrastructure by potentially allowing unauthorized access to router management functions, which could lead to complete network compromise or the installation of persistent backdoors. The implications extend beyond simple device compromise, as routers serve as critical network gateways where successful exploitation could enable attackers to monitor network traffic, redirect connections, or establish persistent access points within the network environment. Organizations and individuals using affected TOTOLINK A3600R devices should immediately implement network segmentation measures and consider disabling unnecessary services while awaiting official patches or firmware updates from the vendor.
The technical implementation of this buffer overflow vulnerability stems from inadequate input validation and memory management practices within the router's firmware. The setdeviceName function fails to properly validate the length of incoming deviceMac and deviceName parameters, allowing attackers to supply data that exceeds the allocated buffer space. This type of vulnerability is particularly dangerous in embedded systems like routers because these devices typically have limited resources and lack the sophisticated memory protection mechanisms found in desktop operating systems. The vulnerability exists at the application layer of the network stack, specifically within the web server component that handles CGI requests, making it accessible through standard HTTP protocols. The use of fixed-length buffers without proper bounds checking creates a predictable attack surface where an attacker can determine the exact amount of data needed to cause the overflow. This vulnerability also aligns with ATT&CK technique T1210, which covers exploitation of remote services, as it allows attackers to leverage the router's web interface to gain unauthorized access. The fact that the vulnerability affects the device name and MAC address parameters suggests that it could be exploited during routine device management operations, making it particularly insidious as it may not immediately trigger suspicion. The buffer overflow could potentially overwrite critical program state information, enabling attackers to redirect program execution flow and execute arbitrary commands with the privileges of the web server process. This makes the vulnerability particularly attractive to attackers who seek to establish persistent access or perform more sophisticated attacks against the network infrastructure. The lack of input sanitization means that the vulnerability is likely to affect all versions of the firmware that contain this specific CGI endpoint, regardless of other security measures that may be in place within the system.
The operational impact of CVE-2024-7174 extends far beyond simple device compromise, as it represents a fundamental weakness in the security architecture of the affected routers. Once exploited, attackers could gain complete administrative control over the router, enabling them to modify network configuration settings, redirect traffic through malicious proxies, or establish persistent backdoors for continued access. The vulnerability's remote exploitability means that attackers do not need physical access to the device, allowing them to target multiple devices simultaneously from anywhere on the internet. This creates a significant threat to network security, as routers often serve as the primary gateway for network traffic and may contain sensitive configuration information that could be used to escalate attacks to other networked devices. The potential for denial of service attacks is also significant, as the buffer overflow could cause the router to crash or restart repeatedly, disrupting network connectivity for all devices connected to that network segment. The vulnerability's presence in the device name and MAC address handling functions suggests that it could be triggered during normal network operations, making detection more difficult and increasing the likelihood of successful exploitation. Organizations using these routers should consider implementing network monitoring solutions that can detect anomalous traffic patterns or unauthorized configuration changes that might indicate exploitation attempts. The public disclosure of the exploit and the vendor's lack of response means that attackers have a clear roadmap for exploitation, potentially leading to widespread compromise of affected devices. The vulnerability also represents a failure in the security lifecycle management of the affected vendor, as it suggests that proper security testing and code review processes were not implemented during firmware development. This type of vulnerability could be particularly devastating in enterprise environments where router compromise could lead to complete network infiltration or the exposure of sensitive corporate data. The timing of the vulnerability disclosure and the vendor's silence indicates a possible lack of security awareness or responsibility within the vendor's security practices, leaving users vulnerable to attacks that could have been prevented through proper patch management and security response protocols.