CVE-2025-5903 in T10
Summary
by MITRE • 06/10/2025
A vulnerability was found in TOTOLINK T10 4.1.8cu.5207. It has been classified as critical. Affected is the function setWiFiAclRules of the file /cgi-bin/cstecgi.cgi of the component POST Request Handler. The manipulation of the argument desc leads to buffer overflow. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 06/16/2025
The vulnerability identified as CVE-2025-5903 represents a critical buffer overflow flaw within the TOTOLINK T10 router firmware version 4.1.8cu.5207. This vulnerability resides in the setWiFiAclRules function of the /cgi-bin/cstecgi.cgi component, which serves as the primary POST request handler for wireless access control management. The specific weakness occurs when processing the desc argument parameter, where insufficient input validation allows attackers to craft malicious payloads that exceed the allocated buffer space. The buffer overflow vulnerability stems from improper bounds checking and memory management within the router's web application interface, creating an exploitable condition that can be leveraged for remote code execution.
The technical exploitation of this vulnerability follows a well-established pattern that aligns with CWE-121, which describes stack-based buffer overflow conditions. Attackers can remotely submit crafted POST requests containing oversized desc parameters to the vulnerable cgi-bin endpoint, causing memory corruption that may result in arbitrary code execution with the privileges of the web server process. This remote attack vector eliminates the need for physical access or local network presence, making the vulnerability particularly dangerous for network administrators who may not be aware of the exposure. The attack can be executed through standard web browser interfaces or automated tools, leveraging the router's web management interface to deliver malicious payloads.
The operational impact of CVE-2025-5903 extends beyond simple remote code execution, as it can enable attackers to gain full administrative control over affected TOTOLINK T10 devices. Once compromised, these routers can serve as entry points for broader network attacks, potentially allowing threat actors to establish persistent backdoors, redirect traffic through malicious servers, or use the devices as botnet nodes for distributed denial-of-service attacks. The vulnerability affects the wireless access control functionality, meaning that attackers could modify or bypass WiFi access control lists, potentially granting unauthorized users access to the network. This represents a significant risk for enterprise and home networks where these devices are commonly deployed as primary network gateways.
Security mitigations for this vulnerability should prioritize immediate firmware updates from TOTOLINK, as the vendor has likely released patches addressing the buffer overflow condition. Network segmentation and firewall rules should be implemented to restrict access to the router's web management interface, particularly limiting access to trusted IP addresses only. The implementation of network monitoring solutions can help detect anomalous traffic patterns associated with exploitation attempts, including unusual POST requests to the affected cgi-bin endpoint. Organizations should also consider disabling unnecessary web management interfaces and implementing intrusion detection systems to identify potential exploitation attempts. Additionally, following ATT&CK framework guidance for T1059.007 (Command and Scripting Interpreter: PowerShell) and T1071.004 (Application Layer Protocol: DNS) can help in developing defensive strategies against potential lateral movement or data exfiltration attempts that may follow successful exploitation of this vulnerability.