CVE-2023-41251 is a stack-based buffer overflow vulnerability classified under CWE-121, found in the boa web server's formRoute functionality within the Realtek rtl819x Jungle SDK version 3.4.11. This SDK is embedded in the LevelOne WBR-6013 router firmware version RER4_A_v3411b_2T2R_LEV_09_170623. The vulnerability arises when the device processes specially crafted HTTP requests, which overflow a stack buffer, allowing an attacker to execute arbitrary code remotely. Exploitation requires the attacker to have network access and elevated privileges (PR:H), but no user interaction is needed (UI:N). The vulnerability affects confidentiality, integrity, and availability, as remote code execution could lead to full device compromise, data interception, or denial of service. Although no public exploits have been reported yet, the vulnerability is rated high severity with a CVSS 3.1 score of 7.2, reflecting its potential impact and ease of exploitation over the network. The lack of available patches or firmware updates increases the urgency for mitigation. The boa web server is commonly used in embedded devices, and the Realtek rtl819x chipset is widely deployed in consumer and enterprise networking hardware, making this vulnerability relevant for a broad range of users. The vulnerability’s presence in a router firmware means it could be leveraged to pivot into internal networks, posing a significant threat to organizational security.

For European organizations, exploitation of CVE-2023-41251 could lead to severe consequences including unauthorized remote code execution on network routers, resulting in potential data breaches, interception of sensitive communications, and disruption of network services. Compromise of the LevelOne WBR-6013 routers could allow attackers to establish persistent footholds within corporate networks, bypass perimeter defenses, and launch further attacks on internal systems. Critical infrastructure sectors such as finance, healthcare, and government agencies relying on these routers for secure connectivity may face operational disruptions and regulatory compliance issues. The vulnerability’s network-based exploit vector and absence of user interaction requirements increase the risk of automated or targeted attacks. Additionally, the absence of known public exploits currently provides a window for proactive defense, but also means organizations must act swiftly to mitigate before exploitation becomes widespread. The impact extends beyond individual devices to the broader network security posture, potentially undermining trust in network infrastructure components.

1. Immediately identify and inventory all LevelOne WBR-6013 routers and other devices running the affected Realtek rtl819x Jungle SDK firmware version RER4_A_v3411b_2T2R_LEV_09_170623 within the network. 2. Restrict network access to router management interfaces by implementing strict access control lists (ACLs) and limiting management access to trusted IP addresses or VPNs. 3. Employ network segmentation to isolate vulnerable devices from critical internal systems and sensitive data. 4. Monitor network traffic for unusual HTTP requests targeting the router’s web interface, particularly those resembling formRoute requests, using intrusion detection/prevention systems (IDS/IPS) with custom signatures. 5. Disable or restrict the boa web server functionality if not required or replace it with a more secure alternative if possible. 6. Engage with LevelOne or Realtek support channels to obtain firmware updates or patches; if unavailable, consider device replacement or alternative secure hardware. 7. Implement strong authentication mechanisms and change default credentials on all affected devices to reduce the risk of privilege escalation. 8. Conduct regular vulnerability assessments and penetration testing focused on network infrastructure devices to detect exploitation attempts early. 9. Educate network administrators on this vulnerability and ensure incident response plans include steps for router compromise scenarios.