CVE-2025-45787 in A3100R
Summary
by MITRE • 05/08/2025
TOTOLINK A3100R V5.9c.1527 is vulnerable to Buffer Overflow viathe comment parameter in setIpPortFilterRules.
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Analysis
by VulDB Data Team • 05/13/2025
The vulnerability identified as CVE-2025-45787 affects the TOTOLINK A3100R router model running firmware version V5.9c.1527. This device is susceptible to a buffer overflow condition that occurs when processing the comment parameter within the setIpPortFilterRules function. The issue represents a critical security flaw that could potentially allow attackers to execute arbitrary code on the affected device. The vulnerability specifically manifests in the handling of user-supplied input through the comment parameter, which is processed without adequate bounds checking or input sanitization. This buffer overflow vulnerability falls under the CWE-121 category of Buffer Overflow, which is classified as a fundamental memory safety issue that has been consistently identified as one of the most prevalent and dangerous classes of software vulnerabilities.
The technical exploitation of this vulnerability occurs when an attacker sends a malformed request containing an excessively long comment parameter to the setIpPortFilterRules endpoint. The router's firmware fails to validate the length of this input parameter, allowing the data to overflow into adjacent memory regions. This memory corruption can potentially overwrite critical program variables, function return addresses, or other control data structures. The operational impact of this vulnerability extends beyond simple denial of service, as successful exploitation could enable remote code execution on the router, allowing attackers to gain full administrative control over the device. This would provide unauthorized access to the network, potentially enabling man-in-the-middle attacks, DNS hijacking, or the ability to redirect network traffic through the compromised device.
From an operational security perspective, the vulnerability presents a significant risk to network infrastructure since routers serve as primary gateways for network traffic. The TOTOLINK A3100R model is commonly deployed in residential and small office environments, making it an attractive target for attackers seeking to establish persistent network footholds. The vulnerability's exploitation requires minimal privileges and can be executed remotely, aligning with ATT&CK technique T1059.007 for Command and Scripting Interpreter. Network defenders should consider this vulnerability as part of the broader attack surface that includes other common router vulnerabilities such as those related to web interface administration and unauthenticated remote access. The impact assessment should include potential data exfiltration, network reconnaissance capabilities, and the possibility of using the compromised device as a pivot point for attacking other systems within the local network.
Mitigation strategies for CVE-2025-45787 should include immediate firmware updates from TOTOLINK if available, as this represents the most effective solution to address the root cause. Network segmentation and access control measures should be implemented to limit the potential impact of exploitation, including restricting administrative access to the router and implementing network monitoring to detect unusual traffic patterns. Security professionals should also consider implementing intrusion detection systems that can identify attempts to exploit buffer overflow vulnerabilities through malformed requests. The vulnerability highlights the importance of input validation and proper memory management in embedded systems, particularly in network infrastructure devices. Organizations should conduct comprehensive vulnerability assessments of their network equipment and implement robust patch management processes to address similar issues in other network devices that may be susceptible to similar buffer overflow conditions. The remediation process should also include network monitoring to detect potential exploitation attempts and ensure that any compromised devices are isolated from the network until complete remediation is achieved.