CVE-2023-30800 is a heap memory corruption vulnerability classified under CWE-787 (Out-of-bounds Write) affecting the web server component of MikroTik RouterOS version 6, specifically versions 6.48.8 and 6.49.9. The vulnerability arises from improper handling of crafted HTTP requests, which allows a remote attacker with no authentication or user interaction to send maliciously crafted HTTP requests that cause an out-of-bounds write in the heap memory of the web server process. This memory corruption leads to a crash of the web interface, which then immediately restarts. While the vulnerability does not allow direct code execution or data confidentiality/integrity compromise, the forced crash and restart can cause denial of service (DoS) conditions, disrupting network management and potentially impacting network availability. RouterOS version 7 is not affected, and the issue was resolved in RouterOS 6.49.10 stable. The CVSS v3.1 base score is 7.5, reflecting high severity due to network attack vector, low attack complexity, no privileges required, no user interaction, and a significant impact on availability. No known exploits have been reported in the wild to date, but the vulnerability’s characteristics make it a candidate for exploitation in the future, especially in environments where MikroTik devices are exposed to untrusted networks. The vulnerability’s root cause is a classic out-of-bounds write, a common memory safety issue that can lead to unpredictable behavior including crashes and potentially more severe exploitation if combined with other vulnerabilities.

For European organizations, the primary impact of CVE-2023-30800 is on availability. The vulnerability can be exploited remotely without authentication, allowing attackers to cause repeated crashes and restarts of the MikroTik RouterOS web interface, which may disrupt network management and monitoring capabilities. This can lead to temporary denial of service conditions affecting network operations, especially in environments where the web interface is critical for device configuration and monitoring. Although the vulnerability does not directly compromise confidentiality or integrity, the loss of availability can have cascading effects on business continuity, incident response, and operational efficiency. Organizations relying on MikroTik RouterOS version 6 in critical infrastructure sectors such as telecommunications, government, finance, and utilities may face increased risk of service interruptions. Additionally, if attackers use this vulnerability as a distraction or part of a multi-stage attack, it could facilitate further exploitation or lateral movement within networks. The lack of required authentication and user interaction increases the risk profile, particularly for devices exposed to the internet or untrusted networks.

1. Immediate upgrade of all MikroTik RouterOS devices running version 6.48.8 or 6.49.9 to version 6.49.10 or later, where the vulnerability is patched. 2. Restrict access to the RouterOS web interface by implementing network segmentation and firewall rules to limit HTTP access only to trusted management networks or IP addresses. 3. Disable the web interface if it is not required for device management, or replace it with secure management methods such as SSH with strong authentication. 4. Monitor network traffic for unusual or malformed HTTP requests targeting MikroTik devices, using intrusion detection/prevention systems (IDS/IPS) with updated signatures. 5. Regularly audit and inventory MikroTik devices to ensure no vulnerable versions remain in production. 6. Implement robust logging and alerting on device crashes and restarts to detect potential exploitation attempts early. 7. Educate network administrators about the vulnerability and the importance of timely patching and access control to reduce exposure.