CVE-2025-4731 in A3002R
Summary
by MITRE • 05/16/2025
A vulnerability classified as critical has been found in TOTOLINK A3002R and A3002RU 3.0.0-B20230809.1615. This affects an unknown part of the file /boafrm/formPortFw of the component HTTP POST Request Handler. The manipulation of the argument service_type leads to buffer overflow. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 06/20/2025
This critical vulnerability exists within the TOTOLINK A3002R and A3002RU router firmware versions 3.0.0-B20230809.1615, specifically within the HTTP POST Request Handler component. The flaw resides in the file /boafrm/formPortFw which processes incoming HTTP POST requests, making it a prime target for remote exploitation. The vulnerability stems from improper input validation when handling the service_type parameter, creating a buffer overflow condition that can be triggered through malformed HTTP requests. This represents a classic buffer overflow vulnerability classified under CWE-121 which occurs when a program writes data beyond the boundaries of a fixed-length buffer, potentially leading to memory corruption and arbitrary code execution. The attack vector is remote, meaning malicious actors can exploit this vulnerability without physical access to the device, making it particularly dangerous for networked environments.
The operational impact of this vulnerability extends beyond simple denial of service, as it enables remote code execution capabilities that could allow attackers to completely compromise affected routers. When an attacker successfully exploits this buffer overflow, they can manipulate the router's memory and potentially gain full administrative control over the device. This compromise could lead to various malicious activities including but not limited to man-in-the-middle attacks, DNS hijacking, traffic interception, and creating backdoors for persistent access. The vulnerability's disclosure status indicates that attackers may already be leveraging this weakness in the wild, making immediate remediation essential. The affected HTTP POST handler component processes network traffic and configuration changes, making it a critical attack surface that could provide attackers with persistent access to the underlying network infrastructure.
Mitigation strategies should prioritize immediate firmware updates from TOTOLINK, as this is the most effective defense against the known exploit. Network administrators should implement strict firewall rules to limit access to router management interfaces and consider disabling unnecessary services that might expose the vulnerable HTTP handler. The implementation of network segmentation can help contain potential compromise, preventing lateral movement within the network. Security monitoring should focus on detecting unusual traffic patterns or attempts to access the vulnerable formPortFw endpoint, with particular attention to POST requests containing malformed service_type parameters. Organizations should also consider network intrusion detection systems that can identify exploitation attempts based on known signature patterns associated with this specific buffer overflow. Additionally, regular security audits should verify that no unauthorized modifications have occurred to router configurations or firmware, as attackers may attempt to maintain persistence through configuration changes or by installing malicious firmware versions. The vulnerability's classification as critical aligns with ATT&CK technique T1059.007 for remote code execution and T1566 for phishing attacks that could leverage the compromised router as a pivot point for broader network infiltration.