CVE-2025-11444 is a buffer overflow vulnerability identified in the TOTOLINK N600R wireless router firmware versions up to 4.3.0cu.7866_B20220506. The vulnerability resides in the HTTP Request Handler component, specifically in the setWiFiBasicConfig function located in the /cgi-bin/cstecgi.cgi script. The issue arises when the 'wepkey' parameter is manipulated with crafted input that exceeds the expected buffer size, causing a buffer overflow condition. This flaw allows a remote attacker to execute arbitrary code or cause a denial of service by sending specially crafted HTTP requests to the router’s web interface. The vulnerability does not require authentication or user interaction, making it highly exploitable over the network. The CVSS v4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, with low attack complexity and no privileges required. Although no active exploits have been reported in the wild, the public disclosure of exploit details increases the likelihood of exploitation attempts. The vulnerability could enable attackers to gain control over the router, intercept or manipulate network traffic, or disrupt network services, posing significant risks to affected environments.

For European organizations, exploitation of CVE-2025-11444 could lead to severe consequences including unauthorized access to internal networks, interception of sensitive communications, and disruption of network availability. Compromised routers can serve as footholds for lateral movement within corporate or governmental networks, potentially leading to data breaches or sabotage of critical infrastructure. Small and medium enterprises relying on TOTOLINK N600R devices for network connectivity may face operational downtime and reputational damage. Additionally, sectors such as finance, healthcare, and public administration, which require high network security, could be particularly vulnerable. The ability to exploit this vulnerability remotely without authentication increases the attack surface, making it easier for threat actors to target organizations across Europe. The lack of patches at the time of disclosure further exacerbates the risk, necessitating immediate mitigation efforts to prevent exploitation.

1. Immediately check for and apply any firmware updates released by TOTOLINK addressing CVE-2025-11444. 2. If no official patch is available, restrict access to the router’s web management interface by implementing network segmentation and firewall rules that block HTTP requests to /cgi-bin/cstecgi.cgi from untrusted sources. 3. Disable remote management features on the router to reduce exposure. 4. Monitor network traffic for unusual HTTP requests targeting the vulnerable endpoint and implement intrusion detection/prevention systems (IDS/IPS) signatures to detect exploitation attempts. 5. Replace affected devices with models from vendors with a stronger security track record if timely patches are not forthcoming. 6. Educate IT staff on the vulnerability and ensure incident response plans include steps to isolate and remediate compromised routers. 7. Conduct regular vulnerability assessments and penetration tests focusing on network infrastructure devices to identify similar risks.