CVE-2020-20211

Mikrotik RouterOS versions 6.40.5 through 6.49.10 (fixed in 7) allow a remote attacker to cause a device crash via crafted packet data to the SMB service on TCP port 445.

MikroTik RouterOS (7.x) accepts malformed RSA/PKCS#1 v1.5 signatures across RSA-based services, including TLS/X.509 certificate validation and SSH host-key authentication. Because the trust store includes an e=3 root CA, an attacker controlling or redirecting outbound TLS can use the root's public certificate to forge a trusted intermediate and issue certificates for arbitrary hostnames, enabling TLS server impersonation. This also undermines RSA-based SSH authentication.

MikroTik RouterOS before 7.25beta4 contains an improper input validation vulnerability in the labelled-VPN NLRI iterators of the routing service. An unauthenticated on-path attacker can send a malformed MP_REACH_NLRI UPDATE message with a prefix-length value below the minimum valid for a labelled-VPN NLRI, which passes validation while describing a route with a negative-length address portion. The fix is carried only in 7.25beta4 (a development build); the current stable release 7.24.2 and the long-term release 7.23.5 both remain affected.

MikroTik firmware 7.19.4 stores sensitive authentication credentials and network state in cleartext within non-volatile storage. An attacker with physical access to the device can extract this material from an SPI flash dump without authenticating and without knowing the administrative password.

MikroTik RouterOS before 7.24 contains a heap memory corruption vulnerability in the userspace SMB daemon that allows remote attackers to corrupt adjacent heap memory by supplying a crafted uniPwdLen value in the SMB1 SessionSetupAndX handler. An attacker can send a malformed SMB1 request with a uniPwdLen field that triggers an integer underflow, causing the resulting value to be used as the copy length in a memory copy operation into a smaller heap buffer, corrupting adjacent heap memory.

MikroTik RouterOS before 7.24.2 contains a path traversal vulnerability in the container package OCI/tar image extraction. An attacker can write files outside the container root by supplying a crafted image with symlinks pointing to arbitrary paths. Via /container/add, this allows root-privileged file creation, directory creation, file deletion via overlayfs whiteout, and hardlink creation on the persistent data partition without starting the container. The 7.23.x long-term branch does not contain the fix.

MikroTik RouterOS before 7.23.4 (long-term) and 7.24.2 (stable) contains a stack-based buffer overflow vulnerability in the mtget binary's TFTP RRQ builder function, allowing authenticated users to crash the mtget worker process by supplying a URL path of 507 bytes or more to the /tool fetch command.

A product with the MikroTik RouterOS API enabled is vulnerable to insufficient session expiration. Active sessions may retain their previous permission set after inactivity timeouts or user-group changes.