CVE-2025-6487 in A3002R
Summary
by MITRE • 06/23/2025
A vulnerability was found in TOTOLINK A3002R 1.1.1-B20200824.0128. It has been rated as critical. This issue affects the function formRoute of the file /boafrm/formRoute. The manipulation of the argument subnet leads to stack-based buffer overflow. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 06/26/2025
The vulnerability identified as CVE-2025-6487 represents a critical stack-based buffer overflow in the TOTOLINK A3002R router firmware version 1.1.1-B20200824.0128. This flaw exists within the formRoute function of the /boafrm/formRoute file, which is part of the web-based administration interface that manages network routing configurations. The vulnerability specifically manifests when processing the subnet argument, indicating that the device fails to properly validate or sanitize input parameters before using them in memory operations. The stack-based nature of this buffer overflow means that malicious input can overwrite adjacent memory locations on the program stack, potentially leading to arbitrary code execution or system crashes. This vulnerability is particularly concerning as it affects a network device's administrative interface, which is typically accessible over the network and may be exposed to unauthenticated attackers. The fact that this exploit has been publicly disclosed and is potentially usable significantly increases the risk profile of affected devices, as it removes the element of zero-day exploitation and makes the vulnerability immediately actionable by threat actors.
The technical implementation of this vulnerability stems from improper input validation within the formRoute function, which likely uses unsafe string handling functions such as strcpy, strcat, or sprintf without adequate bounds checking. When an attacker supplies a maliciously crafted subnet parameter, the application fails to verify that the input length does not exceed the allocated buffer size on the stack. This creates a classic buffer overflow condition where excess data overflows into adjacent memory segments, potentially corrupting the return address or other critical stack variables. The attack vector being remote indicates that an attacker can trigger this vulnerability through network communication without requiring physical access to the device, making it particularly dangerous for network infrastructure. According to CWE guidelines, this represents a CWE-121 stack-based buffer overflow vulnerability, which is categorized as a critical weakness in memory safety. The vulnerability aligns with ATT&CK technique T1210, which involves exploiting weaknesses in remote services to gain unauthorized access, and T1059 which covers command and scripting interpreter usage for persistence.
The operational impact of CVE-2025-6487 extends beyond simple system instability, as it provides potential attackers with a pathway for complete system compromise of affected TOTOLINK A3002R devices. Once exploited, an attacker could gain root access to the router's operating system, enabling them to modify network routing configurations, redirect traffic through malicious servers, or establish persistent backdoors for further attacks. The administrative interface being web-based means that the attack surface includes all standard web application vulnerabilities such as cross-site scripting and injection attacks that could be leveraged in conjunction with this buffer overflow. Network administrators face significant risk as compromised routers can become entry points for broader network infiltration, potentially allowing attackers to pivot to internal network resources and escalate privileges across the enterprise network. The vulnerability's public disclosure status means that threat actors can readily develop automated exploitation tools, increasing the frequency and likelihood of successful attacks against unpatched devices. Organizations relying on these routers for network infrastructure must consider the potential for complete network compromise, as routers often serve as critical gateways between internal and external network segments.
Mitigation strategies for CVE-2025-6487 must address both immediate threat reduction and long-term security posture improvements. The most effective immediate solution involves applying the vendor-provided firmware update that contains the patched formRoute function with proper input validation and bounds checking. Network administrators should also implement network segmentation and access controls to limit exposure of affected routers to untrusted networks, particularly by restricting access to the administrative web interface to trusted IP addresses only. Additional defensive measures include deploying network monitoring solutions to detect unusual traffic patterns or potential exploitation attempts, implementing intrusion detection systems that can identify known exploit signatures, and conducting regular vulnerability assessments to identify similar issues in other network equipment. Organizations should also consider disabling unnecessary services and features on the affected routers, particularly the web interface if it is not essential for operations. The implementation of web application firewalls or security proxies can provide additional protection layers for the administrative interface. According to industry best practices and NIST guidelines for embedded systems security, regular firmware updates and security audits should be part of the operational security program for all network infrastructure devices. Long-term mitigation includes developing incident response procedures specifically for network device compromises and establishing a security awareness program that educates staff on the risks associated with network infrastructure vulnerabilities.