CVE-2025-11528 is a stack-based buffer overflow vulnerability identified in the Tenda AC7 router firmware version 15.03.06.44. The vulnerability resides in an unspecified function handling the /goform/saveAutoQos endpoint, specifically triggered by malicious manipulation of the 'enable' argument. This flaw allows an attacker to overflow the stack buffer, which can lead to arbitrary code execution on the device. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, significantly increasing its risk profile. The CVSS 4.0 base score is 8.7, reflecting high severity due to the ease of exploitation (network vector, low attack complexity), no privileges or user interaction needed, and the potential for full compromise of the device's confidentiality, integrity, and availability. The exploit code is publicly available, which could facilitate attacks by less skilled adversaries. The affected product, Tenda AC7, is a consumer and small business wireless router commonly used for internet connectivity. Exploitation could allow attackers to gain control over the router, intercept or manipulate network traffic, disrupt network services, or pivot into internal networks. No official patches or firmware updates have been linked yet, increasing the urgency for mitigation. The vulnerability's presence in a widely deployed router model makes it a significant threat vector, especially in environments where these devices are used as primary network gateways.

For European organizations, this vulnerability poses a substantial risk to network security and operational continuity. Compromise of Tenda AC7 routers could lead to unauthorized access to internal networks, interception of sensitive data, and disruption of business-critical services. Given the router’s role as a network gateway, attackers could launch further attacks against connected systems, escalate privileges, or exfiltrate confidential information. Small and medium enterprises, home offices, and branch offices that rely on Tenda AC7 devices without robust network segmentation are particularly vulnerable. The availability of a public exploit increases the likelihood of opportunistic attacks, including by cybercriminal groups targeting European entities. Additionally, critical infrastructure sectors such as healthcare, finance, and government agencies using these routers may face heightened risks of espionage or sabotage. The vulnerability could also undermine trust in network reliability and data privacy, leading to regulatory and compliance challenges under frameworks like GDPR. Overall, the impact spans confidentiality, integrity, and availability, with potential cascading effects on organizational security posture.

1. Immediate network segmentation: Isolate Tenda AC7 routers from critical network segments to limit potential lateral movement in case of compromise. 2. Disable or restrict access to the /goform/saveAutoQos endpoint if possible, using router configuration or firewall rules to block unauthorized requests. 3. Monitor network traffic for anomalous requests targeting the vulnerable endpoint, employing intrusion detection/prevention systems with updated signatures. 4. Apply firmware updates as soon as Tenda releases a patch addressing this vulnerability; regularly check vendor advisories. 5. Replace affected routers with models from vendors with a strong security track record if patching is delayed or unavailable. 6. Implement strict access controls on router management interfaces, including changing default credentials and limiting remote management. 7. Educate IT staff about this vulnerability and the risks of using unpatched consumer-grade networking equipment in enterprise environments. 8. Consider deploying network-level protections such as web application firewalls or reverse proxies to filter malicious payloads targeting router endpoints. 9. Conduct regular security assessments and penetration testing to identify and remediate similar vulnerabilities proactively. 10. Maintain an incident response plan that includes steps for containment and recovery from router compromise.