CVE-2025-11527 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/fast_setting_pppoe_set endpoint, specifically in the processing of the Password parameter. An attacker can craft a malicious request with a manipulated Password argument to overflow the stack buffer, potentially overwriting the return address or other control data. This can lead to arbitrary code execution on the device with elevated privileges, as the router firmware typically runs with high system rights. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, making it highly accessible to attackers. The CVSS 4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no prerequisites for exploitation. Although no known exploits have been observed in the wild, the public disclosure of exploit details increases the likelihood of imminent attacks. The lack of an official patch at the time of disclosure necessitates immediate mitigation efforts by affected users. This vulnerability threatens the security of home and enterprise networks relying on Tenda AC7 routers, potentially allowing attackers to gain persistent access, intercept or manipulate traffic, or disrupt network services.

For European organizations, exploitation of CVE-2025-11527 could lead to severe consequences including unauthorized access to internal networks, interception of sensitive communications, and disruption of critical network services. Compromise of routers can serve as a foothold for lateral movement within corporate or governmental networks, increasing the risk of data breaches or espionage. The integrity of network traffic could be undermined, enabling man-in-the-middle attacks or injection of malicious payloads. Availability of network connectivity may be impacted through denial-of-service conditions caused by exploitation or subsequent attacker actions. Organizations in sectors such as finance, healthcare, telecommunications, and government are particularly vulnerable due to their reliance on secure and stable network infrastructure. The remote and unauthenticated nature of the exploit increases the attack surface, especially for devices exposed to the internet or poorly segmented internal networks. The public disclosure of exploit code further elevates the threat level, necessitating urgent attention to prevent exploitation in European environments.

1. Immediately restrict access to the router's management interfaces by disabling remote management features or limiting access to trusted IP addresses only. 2. Segment networks to isolate Tenda AC7 devices from critical infrastructure and sensitive systems, reducing potential lateral movement. 3. Monitor network traffic for unusual or suspicious requests targeting the /goform/fast_setting_pppoe_set endpoint, using IDS/IPS solutions with custom signatures if necessary. 4. Apply any available firmware updates from Tenda as soon as they are released; if no patch is available, consider temporary replacement of vulnerable devices with unaffected models. 5. Enforce strong network perimeter defenses such as firewalls to block unsolicited inbound traffic to router management ports. 6. Conduct regular security audits and vulnerability assessments focusing on network devices to identify and remediate similar risks proactively. 7. Educate IT staff about this vulnerability and the importance of rapid response to public exploit disclosures. 8. If feasible, implement network-level authentication or VPN access for router management to add an additional security layer.