CVE-2025-59365 is a stack-based buffer overflow vulnerability classified under CWE-121, found in certain ASUS router firmware versions (3.0.0.4_386, 3.0.0.4_388, 3.0.0.6_102). This vulnerability arises when an authenticated attacker sends a crafted request to the router, causing the device to process data beyond the allocated stack buffer boundaries. This can lead to memory corruption, resulting in potential denial of service by crashing the device or causing unpredictable behavior that impacts availability. The vulnerability requires the attacker to have authenticated access to the device, implying that remote exploitation would require prior compromise or valid credentials. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no user interaction (UI:N), and high privileges required (PR:H). The impact is primarily on availability (VA:H), with no confidentiality or integrity impact reported. No known exploits have been observed in the wild, but the vulnerability poses a risk to network stability and continuity. ASUS has acknowledged the issue and recommends applying security updates as detailed in their advisory. The vulnerability's exploitation could disrupt business operations relying on affected routers, especially in environments where these devices serve as critical network gateways.

For European organizations, this vulnerability could lead to network outages or degraded performance if exploited, impacting business continuity and operational availability. Organizations relying on ASUS routers in critical infrastructure, enterprise networks, or service provider environments may experience denial of service conditions, potentially disrupting internal communications and internet access. The requirement for authenticated access limits the attack surface but does not eliminate risk, especially if credential compromise occurs through phishing or insider threats. The medium severity rating reflects a significant but not catastrophic impact, emphasizing availability concerns without direct data breach implications. Disruptions could affect sectors such as finance, healthcare, and government services, where network reliability is paramount. Additionally, the lack of known exploits currently reduces immediate risk but does not preclude future exploitation attempts. European organizations should assess their inventory for affected firmware versions and prioritize patching to mitigate potential operational disruptions.

1. Immediately inventory all ASUS routers within the organization to identify devices running affected firmware versions (3.0.0.4_386, 3.0.0.4_388, 3.0.0.6_102). 2. Monitor ASUS security advisories closely and apply firmware updates as soon as official patches are released. 3. Restrict administrative access to routers using network segmentation and strong authentication mechanisms such as multi-factor authentication (MFA) to reduce the risk of credential compromise. 4. Implement strict access control lists (ACLs) to limit management interface exposure to trusted IP addresses only. 5. Regularly audit router logs for unusual or unauthorized access attempts that could indicate exploitation attempts. 6. Employ network intrusion detection/prevention systems (IDS/IPS) tuned to detect anomalous traffic patterns targeting router management interfaces. 7. Educate network administrators on the importance of credential security and recognizing phishing attempts that could lead to credential theft. 8. Consider deploying redundant network paths or failover mechanisms to maintain availability in case of device failure. 9. If immediate patching is not possible, temporarily disable remote management interfaces or restrict them to internal networks to reduce exposure. 10. Maintain up-to-date backups of router configurations to enable rapid recovery if devices become unstable or compromised.