CVE-2024-21778 is a heap-based buffer overflow vulnerability identified in the LevelOne WBR-6013 wireless router, which utilizes the Realtek rtl819x Jungle SDK version 3.4.11. The flaw exists within the mib_init_value_array functionality responsible for processing configuration files, specifically .dat files. An attacker with elevated privileges on the device can upload a maliciously crafted .dat file that triggers a heap overflow, enabling arbitrary code execution. This can lead to full compromise of the device, allowing attackers to execute code with the same privileges as the router’s firmware, potentially altering configurations, intercepting or redirecting traffic, or launching further attacks within the network. The vulnerability requires no user interaction but does require the attacker to have high-level privileges (e.g., authenticated access to the device’s management interface or file upload capability). The CVSS v3.1 base score is 7.2, reflecting network attack vector (AV:N), low attack complexity (AC:L), high privileges required (PR:H), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). No public exploits or patches are currently available, increasing the urgency for affected organizations to implement mitigations. The vulnerability is categorized under CWE-122 (Heap-based Buffer Overflow), a common and dangerous class of memory corruption bugs that can lead to remote code execution. The affected firmware version is RER4_A_v3411b_2T2R_LEV_09_170623, and no alternative patched versions have been published yet. The vulnerability was publicly disclosed on July 8, 2024.

For European organizations, exploitation of this vulnerability could result in complete compromise of affected LevelOne WBR-6013 routers, leading to unauthorized access to internal networks, interception or manipulation of sensitive data, and disruption of network availability. Critical infrastructure, enterprises, and government agencies relying on these routers for secure network connectivity may face increased risks of espionage, data breaches, or denial of service. The ability to execute arbitrary code on the device could allow attackers to establish persistent footholds, bypass network segmentation, and launch further attacks against connected systems. Given the router’s role as a network gateway, the impact extends beyond the device itself, potentially affecting entire organizational networks. The requirement for high privileges limits mass exploitation but does not eliminate risk in environments where attackers can gain initial access or where default or weak credentials are used. The absence of known exploits in the wild currently reduces immediate risk but also means defenders must proactively address the vulnerability before it is weaponized.

1. Immediately audit all LevelOne WBR-6013 devices to identify affected firmware versions and restrict access to management interfaces to trusted administrators only. 2. Enforce strong authentication mechanisms and change default credentials to prevent unauthorized access that could enable file uploads. 3. Disable or restrict the ability to upload configuration files (.dat files) unless absolutely necessary, and implement strict validation controls on any uploaded files. 4. Monitor network traffic and device logs for unusual activity related to configuration changes or file uploads. 5. Engage with LevelOne or authorized vendors to obtain firmware updates or patches as soon as they become available. 6. Consider network segmentation to isolate vulnerable devices from critical infrastructure and sensitive data stores. 7. Employ intrusion detection/prevention systems (IDS/IPS) tuned to detect anomalous behavior or exploitation attempts targeting Realtek SDK vulnerabilities. 8. Maintain an up-to-date asset inventory to quickly identify and remediate affected devices. 9. Educate network administrators on the risks of this vulnerability and ensure incident response plans include steps for compromised network devices. 10. If patching is delayed, consider temporary compensating controls such as disabling remote management or using VPNs with multi-factor authentication for device access.