In Digi RealPort through 4.10.490, authentication relies on a challenge-response mechanism that gives access to the server password, making the protection ineffective. An attacker may send an unauthenticated request to the server. The server will reply with a weakly-hashed version of the server's access password. The attacker may then crack this hash offline in order to successfully login to the server.

An issue was discovered in Digi RealPort through 4.8.488.0. The 'encrypted' mode is vulnerable to man-in-the-middle attacks and does not perform authentication.

An issue was discovered in Digi RealPort for Windows through 4.8.488.0. A buffer overflow exists in the handling of ADDP discovery response messages. This could result in arbitrary code execution.