CVE-2024-7331 in A3300R
Summary
by MITRE • 08/01/2024
A vulnerability was found in TOTOLINK A3300R 17.0.0cu.557_B20221024 and classified as critical. Affected by this issue is the function UploadCustomModule of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument File leads to buffer overflow. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. VDB-273254 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 • 08/01/2024
The vulnerability identified as CVE-2024-7331 represents a critical buffer overflow flaw in the TOTOLINK A3300R router firmware version 17.0.0cu.557_B20221024. This issue resides within the UploadCustomModule function of the /cgi-bin/cstecgi.cgi component, which serves as a critical interface for router administration and firmware management. The vulnerability manifests when processing the File argument, creating an exploitable condition that allows attackers to manipulate memory boundaries through carefully crafted input data. The buffer overflow occurs at the point where user-supplied data is handled without adequate bounds checking, potentially allowing arbitrary code execution within the router's operating environment. This particular implementation flaw affects the router's web-based management interface, making it accessible through standard HTTP protocols.
The technical exploitation of this vulnerability follows a classic buffer overflow attack pattern where an attacker can overwrite adjacent memory locations by providing oversized input data to the File parameter. The attack vector is remote, meaning no physical access to the device is required, and the exploit has already been publicly disclosed, as indicated by VDB-273254 identifier. This remote exploit capability aligns with attack techniques categorized under the MITRE ATT&CK framework in the T1210 category for exploitation of remote services, and specifically relates to T1059 for command and scripting interpreter usage. The vulnerability's classification as critical stems from its potential for complete system compromise, as successful exploitation could enable attackers to gain root access to the router, install persistent backdoors, or modify firmware components to maintain long-term control over the device.
The operational impact of this vulnerability extends beyond individual device compromise to create potential network-wide security risks, particularly in environments where multiple TOTOLINK A3300R devices are deployed. Once compromised, affected routers can serve as entry points for lateral movement within local networks, potentially enabling attackers to pivot to other networked devices. The vulnerability's presence in the firmware management interface means that attackers could potentially upload malicious modules or firmware updates, effectively taking control of the device's core functionality. This type of attack falls under CWE-121, which describes stack-based buffer overflow conditions, and represents a significant risk to network infrastructure security. The lack of vendor response to early disclosure attempts further compounds the risk, as users remain unaware of the vulnerability and unable to obtain patches or mitigations.
Security professionals should implement immediate network monitoring to detect exploitation attempts, particularly focusing on unusual traffic patterns or HTTP requests to the affected cgi-bin endpoint. Network segmentation and access control measures can help limit the potential impact of successful exploitation by preventing lateral movement. The recommended mitigations include disabling unnecessary web management interfaces, implementing firewall rules to restrict access to the router's management ports, and deploying intrusion detection systems to monitor for known exploit signatures. Additionally, organizations should consider implementing device authentication mechanisms and regularly updating firmware to address known vulnerabilities. The vulnerability demonstrates the importance of secure coding practices, specifically in input validation and memory management, as highlighted by CWE-787 which addresses out-of-bounds write conditions. Given that the exploit is publicly available, proactive security measures become essential for protecting network infrastructure from unauthorized access and potential compromise.