CVE-2025-6147 in A702R
Summary
by MITRE • 06/17/2025
A vulnerability was found in TOTOLINK A702R 4.0.0-B20230721.1521. It has been declared as critical. This vulnerability affects unknown code of the file /boafrm/formSysLog of the component HTTP POST Request Handler. The manipulation of the argument submit-url leads to buffer overflow. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 06/23/2025
The vulnerability identified as CVE-2025-6147 represents a critical buffer overflow flaw within the TOTOLINK A702R router firmware version 4.0.0-B20230721.1521. This issue resides in the HTTP POST request handler component, specifically within the /boafrm/formSysLog file which serves as a web interface for system logging configuration. The vulnerability stems from inadequate input validation when processing the submit-url parameter, creating a condition where maliciously crafted input can exceed the allocated buffer space and overwrite adjacent memory regions. The affected device operates using a web-based management interface that processes user inputs through HTTP POST requests, making this vulnerability particularly dangerous as it can be exploited through network-based attacks without requiring physical access to the device.
The technical exploitation of this buffer overflow vulnerability occurs when an attacker submits a specially crafted HTTP POST request containing an excessively long submit-url parameter value. This manipulation allows the attacker to overwrite memory locations adjacent to the vulnerable buffer, potentially enabling arbitrary code execution or system crash conditions. The vulnerability's classification as critical stems from its remote exploitability, meaning that an attacker can initiate the attack from any location on the network without requiring local access to the device. The fact that public exploitation details have been disclosed further amplifies the risk, as malicious actors can immediately leverage this knowledge to target vulnerable devices. According to CWE standards, this vulnerability maps to CWE-121, which describes heap-based buffer overflow conditions, while the attack vector aligns with ATT&CK technique T1210 for exploiting buffer overflows.
The operational impact of this vulnerability extends beyond simple device compromise, as it can potentially enable attackers to gain full administrative control over the affected router. This level of access allows malicious actors to modify network configurations, redirect traffic through malicious servers, establish persistent backdoors, or use the device as a launching point for attacks against other networked systems. The router's position as a network gateway makes it a particularly attractive target, as compromise of this device can provide attackers with a foothold to access the entire internal network. Network administrators face significant challenges in mitigating this vulnerability due to the remote nature of the attack vector and the potential for widespread exploitation across all devices running the affected firmware version. The vulnerability's presence in a consumer-grade router like the TOTOLINK A702R highlights the critical need for proper input validation and memory management practices in embedded systems.
Mitigation strategies for CVE-2025-6147 should prioritize immediate firmware updates from TOTOLINK, as the vendor has likely released patches addressing this specific vulnerability. Network segmentation and firewall rules should be implemented to restrict access to the router's management interface from untrusted networks, while disabling unnecessary services and ports can reduce attack surface. Regular network monitoring should be employed to detect anomalous traffic patterns that might indicate exploitation attempts. Additionally, implementing network intrusion detection systems can help identify and block malicious HTTP POST requests targeting this specific vulnerability. Organizations should also consider conducting vulnerability assessments to identify other potentially affected devices running similar firmware versions, as similar vulnerabilities may exist in other router models. The implementation of secure coding practices and regular security audits in firmware development processes can help prevent similar buffer overflow conditions from occurring in future releases, addressing both the immediate threat and long-term security posture of network infrastructure.