Mikrotik RouterOS before 6.42.7 and 6.40.9 is vulnerable to a memory corruption vulnerability. An authenticated remote attacker can crash the HTTP server by rapidly authenticating and disconnecting.

Mikrotik RouterOS before 6.42.7 and 6.40.9 is vulnerable to a stack exhaustion vulnerability. An authenticated remote attacker can crash the HTTP server via recursive parsing of JSON.

Mikrotik RouterOS before 6.42.7 and 6.40.9 is vulnerable to a memory exhaustion vulnerability. An authenticated remote attacker can crash the HTTP server and in some circumstances reboot the system via a crafted HTTP POST request.

MikroTik RouterOS through 6.42 allows unauthenticated remote attackers to read arbitrary files and remote authenticated attackers to write arbitrary files due to a directory traversal vulnerability in the WinBox interface.

A vulnerability in MikroTik Version 6.41.4 could allow an unauthenticated remote attacker to exhaust all available CPU and all available RAM by sending a crafted FTP request on port 21 that begins with many '\0' characters, preventing the affected router from accepting new FTP connections. The router will reboot after 10 minutes, logging a "router was rebooted without proper shutdown" message.

An issue was discovered in MikroTik RouterOS 6.41.4. Missing OpenVPN server certificate verification allows a remote unauthenticated attacker capable of intercepting client traffic to act as a malicious OpenVPN server. This may allow the attacker to gain access to the client's internal network (for example, at site-to-site tunnels).

A buffer overflow was found in the MikroTik RouterOS SMB service when processing NetBIOS session request messages. Remote attackers with access to the service can exploit this vulnerability and gain code execution on the system. The overflow occurs before authentication takes place, so it is possible for an unauthenticated remote attacker to exploit it. All architectures and all devices running RouterOS before versions 6.41.3/6.42rc27 are vulnerable.

MikroTik RouterBOARD v6.39.2 and v6.40.5 allows an unauthenticated remote attacker to cause a denial of service by connecting to TCP port 53 and sending data that begins with many '\0' characters, possibly related to DNS.

MikroTik v6.40.5 devices allow remote attackers to cause a denial of service via a flood of ICMP packets.

A vulnerability in MikroTik Version 6.38.5 could allow an unauthenticated remote attacker to exhaust all available CPU via a flood of UDP packets on port 500 (used for L2TP over IPsec), preventing the affected router from accepting new connections; all devices will be disconnected from the router and all logs removed automatically.