When SMEs choose to rent servers to support business operations, they often put cost and performance first and ignore network security risks. In fact, with the expansion of business scale and the advancement of digitalization, security threats are also evolving. First, distributed denial of service (DDoS) attacks are not uncommon among SMEs. Attackers exhaust bandwidth and computing resources through massive requests, which will cause websites or applications to be inaccessible for a short period of time. Because SMEs often lack high-defense capabilities or elastic bandwidth guarantees, service interruptions are very likely to occur when encountering hundreds of Gbps of traffic flooding.

Second, vulnerability exploitation is another major risk faced by SMEs. When running operating systems, databases, and applications on rented servers, if patches are not updated in time, attackers can obtain system permissions or execute arbitrary code through known vulnerabilities. Many SMEs often delay the update of operating systems and third-party components due to the lack of professional operation and maintenance teams, and these patches are an important barrier to prevent remote code execution and privilege escalation attacks.

Third, weak passwords and unauthorized access are also prominent. When deploying servers, SMEs sometimes use default administrator accounts or simple passwords. Locked password policies and multi-factor authentication fail to be effectively implemented, allowing attackers to easily enter the system through brute force or dictionary attacks. Once an account is leaked, it may lead to serious consequences such as database leaks or backdoor implants.

Fourth, lax internal security management is also a challenge. SMEs often lack a complete permission separation and log audit mechanism. After employees leave or change roles, they fail to reclaim account permissions in time, allowing former employees or non-related personnel to still access key resources. In addition, insufficient monitoring of server operation and maintenance logs and security logs makes it difficult to detect abnormal behavior or intrusion traces in the first place, and the cost of tracing back afterwards is high and time-consuming.

Fifth, imperfect encrypted communication and data protection mechanisms also affect business security. Many SMEs do not fully enable HTTPS/TLS encryption between internal systems or when interacting with customers, resulting in sensitive data (such as login credentials, customer information) being eavesdropped or tampered with during transmission. Data storage on disks also lacks encryption measures. Once the server or storage medium is illegally obtained, the risk of data leakage is extremely high.

Sixth, cross-regional or cloud hybrid deployment increases network complexity and attack surface. In pursuit of cost and regional coverage, SMEs often deploy part of their business on third-party public clouds or CDN nodes, which introduces public network access paths. If strict network isolation and firewall rules are not set, attackers can initiate scans and intrusions through public network APIs or management ports, and then move laterally to the intranet or other key business services.

Seventh, supply chain risks cannot be ignored. During the server rental process, if the selected image or pre-configured environment contains malicious plug-ins, Trojans or backdoors, attackers can use this to obtain long-term hidden access rights. When choosing operating system distributions, Docker images or commercial software, SMEs need to verify the supplier's qualifications and image integrity, otherwise they may fall into the trap.

Finally, compliance and audit pressures pose a challenge to SMEs. With the implementation of regulations such as GDPR and the Cybersecurity Law, enterprises need to strictly monitor customer data access, storage and transmission, and submit security assessment reports regularly. If SMEs lack compliance teams or professional tools, it is difficult to complete vulnerability scanning, penetration testing and compliance audits, which can easily trigger regulatory penalties or legal disputes.

In response to the above security challenges, small and medium-sized enterprises should take the following measures: First, deploy DDoS high defense and traffic cleaning, and cooperate with rental service providers or third-party security vendors to ensure business bandwidth redundancy and cleaning capabilities; second, establish a timely patch management mechanism, and quickly push updates after verification in the test environment through automated tools; third, implement strong password policies and multi-factor authentication, and whitelist and port knocking protection for management ports such as SSH and RDP; fourth, improve internal authority management, assign user roles according to the principle of least privilege, enable centralized log collection and SIEM platform for real-time alarms for abnormal events; fifth, fully enable HTTPS/TLS and disk data encryption, and do a good job of key life cycle management; sixth, perform network segmentation and security group management for cloud and hybrid deployments, use dedicated lines to connect key resources, and do not expose management interfaces to the public network; seventh, purchase certified official images and software, regularly perform image integrity verification, and sign security assurance agreements with suppliers; eighth, formulate compliance processes and annual security audit plans, introduce third-party security assessment agencies to conduct penetration tests, and prepare necessary documents and reports according to compliance requirements.

Through the above systematic security protection and management, small and medium-sized enterprises can not only deal with common network attacks when renting servers, but also improve the overall security level and support the continuous and stable development of the business.