CVE-2025-7527 is a critical security vulnerability identified in the Tenda FH1202 router, specifically version 1.2.0.14(408). The flaw exists in the function fromAdvSetWan within the /goform/AdvSetWan endpoint. This vulnerability is a stack-based buffer overflow triggered by improper handling of the PPPOEPassword argument. An attacker can remotely exploit this flaw by sending a specially crafted request to the vulnerable endpoint, causing the router to overwrite memory on the stack. This can lead to arbitrary code execution, potentially allowing the attacker to take full control of the device without requiring authentication or user interaction. The vulnerability has a CVSS 4.0 base score of 8.7, indicating a high severity level. The attack vector is network-based (AV:N), with low attack complexity (AC:L), no privileges required (PR:L), and no user interaction needed (UI:N). The impact on confidentiality, integrity, and availability is high (VC:H, VI:H, VA:H), meaning an attacker could exfiltrate sensitive data, alter device configurations, or disrupt network services. Although no public exploits have been reported in the wild yet, the vulnerability details have been disclosed, increasing the risk of exploitation by threat actors. The lack of an official patch or mitigation from the vendor at the time of publication further elevates the threat level. This vulnerability is particularly dangerous because routers like the Tenda FH1202 are often deployed in home and small office environments, serving as critical gateways to the internet and internal networks. Compromise of such devices can lead to broader network infiltration, interception of traffic, and persistent access for attackers.

For European organizations, the exploitation of CVE-2025-7527 could have significant consequences. Many small and medium enterprises (SMEs) and residential users rely on consumer-grade routers like the Tenda FH1202 for internet connectivity. A successful attack could allow adversaries to intercept confidential communications, manipulate network traffic, or establish persistent footholds within corporate or home networks. This could lead to data breaches, intellectual property theft, or disruption of business operations. Additionally, compromised routers could be leveraged as part of botnets to launch distributed denial-of-service (DDoS) attacks against critical infrastructure or other targets within Europe. The high severity and remote exploitability make this vulnerability a substantial risk, especially in environments where network segmentation and advanced security controls are limited. Given the critical role of routers in network security, exploitation could also undermine trust in network integrity and availability, impacting sectors such as finance, healthcare, and government services that require reliable and secure connectivity.

To mitigate the risk posed by CVE-2025-7527, European organizations and users should take immediate and specific actions: 1) Identify all Tenda FH1202 devices running firmware version 1.2.0.14(408) within their networks through asset inventories or network scanning tools. 2) Since no official patch is currently available, consider temporarily disabling remote management interfaces or restricting access to the /goform/AdvSetWan endpoint via firewall rules or access control lists to prevent external exploitation. 3) Replace vulnerable devices with updated hardware or routers from vendors with active security support if feasible. 4) Monitor network traffic for unusual patterns indicative of exploitation attempts, such as unexpected outbound connections or anomalous HTTP requests targeting router management endpoints. 5) Implement network segmentation to isolate vulnerable devices from critical systems and sensitive data. 6) Educate users about the risks of using default or outdated router firmware and encourage regular updates once patches become available. 7) Engage with Tenda support channels to obtain information on forthcoming patches or recommended workarounds. 8) Employ intrusion detection/prevention systems (IDS/IPS) tuned to detect exploitation attempts targeting this vulnerability. These targeted measures go beyond generic advice by focusing on immediate containment, detection, and long-term remediation strategies tailored to the specific vulnerability and affected product.