CVE-2025-44877 is a critical command injection vulnerability identified in the Tenda AC9 router firmware version V15.03.06.42_multi. The vulnerability exists within the formSetSambaConf function, specifically through the usbname parameter. An attacker can exploit this flaw by sending a specially crafted request that manipulates the usbname parameter, allowing arbitrary command execution on the affected device. This type of vulnerability (CWE-77) is particularly dangerous because it enables remote attackers to execute system-level commands without any authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The vulnerability impacts confidentiality, integrity, and availability, as attackers can potentially take full control of the device, intercept or alter network traffic, disrupt network services, or use the compromised router as a pivot point for further attacks within the network. The CVSS score of 9.8 reflects the critical nature of this vulnerability, emphasizing its ease of exploitation and severe impact. Although no known exploits are currently reported in the wild, the high severity and public disclosure mean that exploitation attempts are likely to emerge rapidly. The lack of an official patch or vendor project information at the time of publication further increases the risk for affected users. The vulnerability affects a widely used consumer-grade router model, which is often deployed in home and small office environments, potentially exposing a large attack surface if left unmitigated.

For European organizations, the exploitation of CVE-2025-44877 could have significant consequences. Many small and medium enterprises (SMEs) and even some larger organizations rely on consumer-grade routers like the Tenda AC9 for internet connectivity, especially in branch offices or remote work setups. A successful attack could lead to unauthorized access to internal networks, data exfiltration, disruption of business operations, and the establishment of persistent footholds for further cyberattacks. Given the router’s role as a gateway device, compromise could allow attackers to intercept sensitive communications, manipulate traffic, or launch attacks against other internal systems. This is particularly concerning for sectors with strict data protection requirements under GDPR, such as finance, healthcare, and critical infrastructure. Additionally, the vulnerability could be leveraged in botnet campaigns or distributed denial-of-service (DDoS) attacks, impacting service availability. The absence of authentication and user interaction requirements lowers the barrier for attackers, increasing the likelihood of widespread exploitation if mitigations are not promptly applied.

1. Immediate network segmentation: Isolate affected Tenda AC9 routers from critical internal networks to limit potential lateral movement in case of compromise. 2. Disable Samba sharing features if not required, as the vulnerability is linked to the Samba configuration function. 3. Monitor network traffic for unusual command execution patterns or unexpected outbound connections originating from the router. 4. Apply any available firmware updates from Tenda as soon as they are released; if no official patch is available, consider temporary replacement with alternative secure hardware. 5. Implement strict firewall rules to restrict management interface access to trusted IP addresses only, reducing exposure to remote exploitation. 6. Conduct regular vulnerability scans and penetration tests focusing on network edge devices to detect exploitation attempts early. 7. Educate users and administrators about the risks of using consumer-grade routers in enterprise environments and encourage deployment of enterprise-grade network equipment with robust security features.