CVE-2024-1003 in N200RE
Summary
by MITRE • 01/29/2024
A vulnerability, which was classified as critical, has been found in Totolink N200RE 9.3.5u.6139_B20201216. Affected by this issue is the function setLanguageCfg of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument lang leads to stack-based buffer overflow. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. The identifier of this vulnerability is VDB-252272. 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 • 02/21/2024
This critical vulnerability exists in the Totolink N200RE router firmware version 9.3.5u.6139_B20201216 and specifically affects the setLanguageCfg function within the /cgi-bin/cstecgi.cgi file. The flaw manifests as a stack-based buffer overflow when processing the lang argument, representing a fundamental security weakness that allows attackers to manipulate memory structures through crafted input parameters. The vulnerability's classification as critical indicates severe potential impact on system integrity and availability, as demonstrated by the public disclosure of working exploit code that can be immediately leveraged by threat actors.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations including return addresses and function parameters. The attack vector is remote, meaning no physical access or local network presence is required to exploit the vulnerability, making it particularly dangerous for widespread deployment. This characteristic places the vulnerability within the ATT&CK framework's T1210 category for Exploitation of Remote Services, where adversaries target network accessible services to gain unauthorized access or execute arbitrary code.
The operational impact of this vulnerability extends beyond simple exploitation to potentially enable full system compromise, as buffer overflows in web application interfaces often provide attackers with opportunities to execute arbitrary commands or gain root-level access to affected devices. Given that the affected router is a consumer-grade networking device, the exploitation could lead to complete network infiltration, data exfiltration, or the creation of persistent backdoors within home or small office networks. The lack of vendor response to early disclosure attempts compounds the risk, leaving users without official patches or mitigation guidance during an active exploit period.
Mitigation strategies should focus on immediate network segmentation and access control measures to limit exposure, as well as firmware updates once available from the vendor. Network administrators should implement monitoring for suspicious traffic patterns that may indicate exploitation attempts, particularly targeting the specific CGI endpoint. The vulnerability demonstrates the importance of proper input validation and bounds checking in web applications, as well as the critical need for vendors to maintain responsive security communication channels with the research community. Organizations should also consider implementing network access controls to restrict access to administrative interfaces and ensure that default credentials are changed immediately upon device deployment.