CVE-2025-11324 is a stack-based buffer overflow vulnerability identified in the Tenda AC18 router firmware version 15.03.05.19(6318). The vulnerability resides in an unspecified functionality related to the /goform/setNotUpgrade endpoint, specifically in the handling of the newVersion argument. Improper input validation or bounds checking allows an attacker to supply crafted input that overflows the stack buffer, potentially overwriting control data such as return addresses. This flaw can be triggered remotely over the network without requiring authentication or user interaction, making it highly exploitable. The vulnerability's CVSS 4.0 score is 8.7 (high severity), reflecting its network attack vector, low complexity, no privileges required, and no user interaction needed, combined with high impact on confidentiality, integrity, and availability. Exploitation could allow an attacker to execute arbitrary code with elevated privileges on the router, leading to full device compromise. While no active exploitation has been reported, a public exploit exists, increasing the urgency for mitigation. The vulnerability affects a widely used consumer and small business router model, which is common in various global markets. No official patches or vendor advisories are currently linked, so interim mitigations are critical. The vulnerability's presence in a network gateway device makes it a significant risk for network security and privacy.

The impact of CVE-2025-11324 is substantial for organizations relying on Tenda AC18 routers. Successful exploitation can lead to complete compromise of the router, allowing attackers to execute arbitrary code with elevated privileges. This can result in interception or manipulation of network traffic, disruption of network availability, unauthorized access to internal networks, and potential lateral movement to other systems. The confidentiality, integrity, and availability of organizational networks are at risk. Since the vulnerability is remotely exploitable without authentication or user interaction, attackers can launch automated attacks at scale. This poses a threat not only to individual users but also to enterprises and service providers using these devices as part of their infrastructure. The availability of a public exploit further increases the likelihood of exploitation attempts. Organizations may face data breaches, service outages, and reputational damage if the vulnerability is exploited. Additionally, compromised routers could be used as footholds for broader cyber campaigns or botnet recruitment.

1. Monitor Tenda’s official channels for firmware updates addressing CVE-2025-11324 and apply patches immediately upon release. 2. Until patches are available, restrict access to the router’s management interfaces, especially the /goform/setNotUpgrade endpoint, by implementing network segmentation and firewall rules limiting inbound traffic to trusted sources only. 3. Disable remote management features if not required to reduce the attack surface. 4. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or anomaly detection capable of identifying exploitation attempts targeting this vulnerability. 5. Regularly audit router configurations and logs for suspicious activity indicative of exploitation attempts. 6. Replace affected devices with models from vendors with timely security support if patching is not feasible. 7. Educate network administrators about the risk and ensure incident response plans include steps for handling router compromises. 8. Use network-level protections such as VPNs or zero-trust access to limit exposure of critical network devices. These measures go beyond generic advice by focusing on immediate risk reduction through access control and monitoring while awaiting vendor remediation.