CVE-2022-45522 is a high-severity stack overflow vulnerability identified in the Tenda W30E router firmware version V1.0.1.25(633). The vulnerability arises from improper handling of the 'page' parameter in the HTTP request to the endpoint /goform/SafeClientFilter. Specifically, the router’s web interface does not adequately validate or sanitize the input length or content of this parameter, leading to a stack-based buffer overflow (CWE-787). This type of vulnerability can allow an unauthenticated remote attacker to send a specially crafted HTTP request to the affected endpoint, triggering the overflow. The overflow can corrupt the stack memory, potentially leading to denial of service (DoS) by crashing the device or, in some cases, arbitrary code execution if the attacker can control the overwritten data. The CVSS 3.1 base score of 7.5 reflects a high severity, with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no impact on confidentiality or integrity (C:N/I:N), but high impact on availability (A:H). No known exploits are reported in the wild, and no patches have been published as of the vulnerability disclosure date (December 8, 2022). The vulnerability affects a specific Tenda router model and firmware version, which is commonly used in home and small office environments. The lack of authentication and user interaction requirements makes this vulnerability particularly dangerous, as it can be exploited remotely by any attacker with network access to the device’s management interface, often exposed on local networks or potentially on the internet if misconfigured.

For European organizations, the primary impact of this vulnerability lies in the potential disruption of network availability. The Tenda W30E router is typically deployed in small office/home office (SOHO) environments, which are common in small businesses and remote work setups. Exploitation could lead to denial of service, causing network outages, loss of internet connectivity, and interruption of business operations. While the vulnerability does not directly compromise data confidentiality or integrity, the resulting downtime can affect productivity and may indirectly impact security monitoring or remote access capabilities. Additionally, if attackers leverage the overflow for code execution, they could potentially pivot into internal networks, escalating risks. European organizations relying on Tenda W30E devices without proper segmentation or exposure controls are at risk. The absence of known exploits reduces immediate threat but does not eliminate risk, especially given the ease of exploitation and lack of authentication. The impact is more pronounced for sectors with critical reliance on continuous connectivity, such as small financial offices, healthcare clinics, or remote administrative units.

1. Immediate mitigation involves isolating the affected Tenda W30E devices from untrusted networks, especially the internet, to prevent remote exploitation. 2. Disable remote management interfaces or restrict access via firewall rules to trusted IP addresses only. 3. Monitor network traffic for unusual HTTP requests targeting /goform/SafeClientFilter and implement intrusion detection signatures to flag potential exploit attempts. 4. Replace or upgrade affected devices where possible; if no firmware patch is available, consider migrating to alternative router models with active security support. 5. For organizations with many remote or home office users, provide secure VPN access to reduce direct exposure of vulnerable devices. 6. Regularly audit network device firmware versions and configurations to identify and remediate vulnerable equipment. 7. Engage with Tenda support channels to request firmware updates or security advisories and subscribe to vulnerability notification services for timely patching. These steps go beyond generic advice by focusing on network segmentation, access control, and proactive monitoring tailored to the specific vulnerability and device context.