CVE-2025-8300 is a high-severity heap-based buffer overflow vulnerability identified in the Realtek rtl81xx SDK Wi-Fi driver, specifically within the function N6CSet_DOT11_CIPHER_DEFAULT_KEY. This vulnerability arises due to improper validation of the length of user-supplied data before copying it into a fixed-length heap buffer. The flaw allows a local attacker, who already has the ability to execute low-privileged code on the affected system, to overflow the heap buffer, leading to arbitrary code execution with SYSTEM-level privileges. This escalation of privilege can compromise the confidentiality, integrity, and availability of the system. The vulnerability is classified under CWE-122 (Heap-based Buffer Overflow) and has a CVSS 3.0 base score of 8.8, reflecting its high impact and relatively low complexity to exploit given local access. The vulnerability does not require user interaction but does require local privileges, meaning an attacker must first gain limited code execution on the target device. No public exploits have been reported in the wild yet, and no patches are currently linked, indicating that affected organizations should prioritize mitigation and monitoring. The rtl81xx SDK is commonly embedded in Wi-Fi drivers used in various devices, including laptops and embedded systems, making this vulnerability relevant for environments where Realtek Wi-Fi hardware and drivers are deployed.

For European organizations, this vulnerability poses a significant risk, especially in sectors relying heavily on Realtek Wi-Fi hardware such as enterprise IT, telecommunications, manufacturing, and critical infrastructure. Successful exploitation could allow attackers to escalate privileges from a low-privileged user or compromised application to SYSTEM level, enabling full control over affected devices. This could lead to data breaches, deployment of persistent malware, lateral movement within networks, and disruption of services. Given the widespread use of Realtek Wi-Fi chipsets in consumer and enterprise devices, the scope of impact could be broad. Organizations with remote or hybrid workforces using laptops with vulnerable drivers are particularly at risk. Additionally, the vulnerability could be leveraged as part of multi-stage attacks where initial foothold is gained through phishing or other means, followed by privilege escalation via this flaw. The lack of public exploits currently provides a window for proactive defense, but the high severity score underscores the urgency of addressing this issue to prevent potential exploitation.

1. Immediate inventory and identification of devices using the affected Realtek rtl81xx SDK version 1030.38.712.2019 or similar vulnerable versions. 2. Monitor vendor communications closely for official patches or driver updates from Realtek and apply them promptly upon release. 3. Implement strict application whitelisting and endpoint protection to prevent unauthorized code execution at low privilege levels, reducing the likelihood of initial compromise. 4. Employ least privilege principles and restrict local user permissions to minimize the ability of attackers to execute code locally. 5. Use network segmentation to limit lateral movement from compromised devices. 6. Enable and monitor system logs and security event logs for unusual privilege escalation attempts or suspicious driver behavior. 7. Consider deploying host-based intrusion detection systems (HIDS) that can detect heap overflow exploitation patterns. 8. For critical environments, consider temporary disabling or restricting use of vulnerable Wi-Fi drivers if feasible until patches are available. 9. Educate users on phishing and social engineering risks to reduce the chance of initial low-privilege code execution. These steps go beyond generic advice by focusing on controlling the initial attack vector and monitoring for exploitation attempts specific to this vulnerability’s characteristics.