CVE-2024-42545 identifies a critical buffer overflow vulnerability in the TOTOLINK A3700R router firmware version 9.1.2u.5822_B20200513. The vulnerability resides in the setWizardCfg function, specifically in the handling of the ssid parameter. A buffer overflow occurs when the input exceeds the allocated buffer size, allowing an attacker to overwrite adjacent memory. This flaw is exploitable remotely over the network without requiring authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The vulnerability is classified under CWE-120, which pertains to classic buffer overflow issues that can lead to arbitrary code execution. Given the high CVSS score of 9.8, exploitation can result in complete compromise of the router, including unauthorized control, data interception, or denial of service. The vulnerability was published on August 12, 2024, but no patches or official fixes have been released yet, and no active exploitation has been reported. The TOTOLINK A3700R is a consumer and small business router, which may be widely deployed in various regions, increasing the attack surface. Attackers could leverage this vulnerability to pivot into internal networks or disrupt network services.

The impact of CVE-2024-42545 is severe for organizations and individuals using the TOTOLINK A3700R router. Exploitation can lead to full device compromise, allowing attackers to execute arbitrary code with system-level privileges. This can result in interception or manipulation of network traffic, unauthorized access to internal networks, disruption of internet connectivity, and potential lateral movement to other systems. Confidentiality is at risk as attackers could capture sensitive data passing through the router. Integrity and availability are also compromised, as attackers could alter router configurations or cause denial of service. Given the router’s role as a network gateway, the vulnerability poses a significant risk to enterprise, small business, and home networks. The lack of available patches increases the urgency for mitigation. Organizations relying on this device for critical communications or infrastructure are particularly vulnerable to espionage, sabotage, or ransomware attacks stemming from this flaw.

Until an official patch is released, organizations should implement specific mitigations to reduce risk. First, isolate the TOTOLINK A3700R routers from direct exposure to untrusted networks by placing them behind additional firewalls or VPNs to restrict external access to management interfaces. Disable remote management features if enabled to prevent external exploitation. Monitor network traffic for unusual activity or attempts to exploit the ssid parameter. Consider replacing affected devices with alternative routers from vendors with active security support. If replacement is not immediately feasible, restrict access to the router’s web interface and services to trusted internal IP addresses only. Regularly audit router configurations and firmware versions to detect unauthorized changes. Employ network segmentation to limit potential lateral movement if a device is compromised. Stay informed about vendor advisories for patch releases and apply updates promptly once available. Additionally, educate users about the risks and signs of network compromise related to router vulnerabilities.