Mikrotik RouterOS before 6.42.7 and 6.40.9 is vulnerable to stack buffer overflow through the license upgrade interface. This vulnerability could theoretically allow a remote authenticated attacker execute arbitrary code on the system.

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 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.

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.

A vulnerability in the network stack of MikroTik Version 6.38.5 released 2017-03-09 could allow an unauthenticated remote attacker to exhaust all available CPU via a flood of TCP RST packets, preventing the affected router from accepting new TCP connections.