CVE-2025-70648 identifies a stack overflow vulnerability in the Tenda AX1803 router firmware version 1.0.0.1, specifically within the sub_727F4 function that processes the security_5g parameter. This vulnerability is classified under CWE-121 (stack-based buffer overflow), which occurs when input data exceeds the buffer's capacity, overwriting adjacent memory and potentially causing program crashes or arbitrary code execution. In this case, the crafted input leads to a denial of service (DoS) by crashing the device or its networking services. The vulnerability can be exploited remotely without authentication or user interaction, as the attacker only needs to send a specially crafted request to the affected parameter. The CVSS v3.1 score is 7.5 (high), reflecting the network vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no impact on confidentiality or integrity (C:N, I:N), but high impact on availability (A:H). No patches or known exploits are currently available, indicating the vulnerability is newly disclosed. The lack of affected version details beyond the firmware version suggests the issue is specific to this release. This vulnerability primarily threatens the availability of network services provided by the Tenda AX1803 router, potentially disrupting connectivity for users and dependent systems.

For European organizations, the primary impact of CVE-2025-70648 is the potential disruption of network availability due to denial of service on Tenda AX1803 routers. This can affect enterprise networks, small and medium businesses, and critical infrastructure relying on these devices for wireless connectivity. Network outages could lead to operational downtime, loss of productivity, and interruption of services. In sectors such as healthcare, finance, and public administration, such disruptions could have cascading effects on service delivery and compliance with regulatory requirements. Since the vulnerability does not affect confidentiality or integrity, data breaches are unlikely; however, the loss of availability can still cause significant operational and reputational damage. The ease of exploitation without authentication increases the risk of opportunistic attacks, especially in environments where these routers are exposed to untrusted networks or the internet. The absence of known exploits in the wild provides a window for proactive mitigation, but organizations must act swiftly to prevent potential exploitation.

European organizations should implement the following specific measures to mitigate CVE-2025-70648: 1) Immediately inventory and identify all Tenda AX1803 routers in use, focusing on firmware version 1.0.0.1. 2) Monitor Tenda’s official channels for firmware updates or security advisories addressing this vulnerability and apply patches promptly once available. 3) Restrict access to router management interfaces by implementing network segmentation and firewall rules to limit exposure to trusted internal networks only. 4) Disable remote management features if not required, or enforce strong authentication and encrypted management protocols. 5) Employ intrusion detection/prevention systems (IDS/IPS) to monitor for anomalous or malformed requests targeting the security_5g parameter or related functions. 6) Conduct regular network traffic analysis to detect potential exploitation attempts. 7) Consider replacing vulnerable devices with models from vendors with stronger security track records if patching is delayed. 8) Educate IT staff on recognizing signs of DoS attacks and establishing incident response procedures to quickly isolate affected devices. These steps go beyond generic advice by focusing on device-specific controls and proactive monitoring tailored to the vulnerability’s characteristics.