CVE-2025-9828 is a vulnerability identified in the Tenda CP6 router firmware version 11.10.00.243. The flaw resides in the function sub_2B7D04 within the uhttp component, which is responsible for handling HTTP-related operations. The vulnerability involves the use of a risky cryptographic algorithm, which could potentially weaken the security guarantees of cryptographic operations performed by the device. This weakness can be exploited remotely without requiring authentication or user interaction, but the attack complexity is high and exploitability is difficult. The vulnerability does not directly lead to immediate compromise such as remote code execution or denial of service but may allow attackers to undermine confidentiality or integrity of communications or stored data by exploiting weak cryptographic primitives. The CVSS v4.0 base score is 6.3 (medium severity), reflecting network attack vector, high attack complexity, no privileges or user interaction required, and limited impact on integrity (low) with no impact on confidentiality or availability. Although no known exploits are currently in the wild, the vulnerability has been publicly disclosed, increasing the risk of future exploitation attempts. The absence of patches or mitigation links suggests that users of the affected firmware version should be cautious and monitor for vendor updates.

For European organizations, the impact of this vulnerability could be significant in environments where Tenda CP6 routers are deployed, especially in small to medium enterprises or home office settings where such consumer-grade or SMB-grade equipment is common. The risky cryptographic algorithm could allow attackers to intercept or manipulate sensitive data transmitted through the device, potentially compromising confidentiality and integrity of communications. This is particularly concerning for organizations handling personal data under GDPR, as any data leakage or manipulation could lead to regulatory penalties and reputational damage. The medium severity and difficult exploitability mean that while widespread exploitation is less likely, targeted attacks against high-value targets or critical infrastructure using these devices could still pose a risk. Additionally, the lack of authentication or user interaction required lowers the barrier for remote attackers to attempt exploitation, increasing the threat surface. The vulnerability may also undermine trust in network security controls, requiring organizations to reassess their device security posture and cryptographic standards.

1. Immediate mitigation should include identifying all Tenda CP6 devices running firmware version 11.10.00.243 within the network and isolating them from critical network segments until a patch is available. 2. Monitor vendor communications closely for firmware updates or security advisories addressing this vulnerability and apply patches promptly once released. 3. Where possible, replace affected devices with models from vendors with stronger security track records or that have received recent security updates. 4. Implement network segmentation and firewall rules to restrict remote access to management interfaces of Tenda CP6 devices, reducing exposure to potential remote attacks. 5. Employ network monitoring and intrusion detection systems to detect anomalous traffic patterns that may indicate exploitation attempts targeting the cryptographic weakness. 6. Review and enhance cryptographic policies across the organization to ensure use of strong, standardized algorithms and protocols, minimizing reliance on device-level cryptography that may be vulnerable. 7. For sensitive environments, consider deploying additional encryption layers (e.g., VPNs, TLS) independent of the device’s cryptographic functions to protect data confidentiality and integrity.