FastNetMon Community Edition releases up to 1.2.9 run a gRPC API server on port 50052 that is started with insecure credentials, and the code comments confirm that no authentication is performed. The RPC methods exposed—ExecuteBan, ExecuteUnban, GetBanlist, GetTotalTrafficCounters, and others that call popen()—do not perform any credential checking, allowing an attacker to trigger administrative actions. An attacker who can reach the endpoint can ban IP addresses, which can silently blackhole legitimate traffic; unban calls can disable active DoS protection, and the popen() wrapper can execute arbitrary scripts, effectively providing remote code execution. The weakness stems from missing authentication and lack of role‑based access control, a classic improper access control flaw.

All shipped FastNetMon Community Edition binaries released through v1.2.9 contain this flaw. No other vendors or product versions are listed in the CVE payload; thus only the Community Edition source code packaged in these releases is affected. The vulnerability is triggered by the gRPC listener on TCP port 50052 and is present regardless of network topology, although the description notes that local network reachability is sufficient to exploit it. Based on the description, it is inferred that only the Community Edition up to version 1.2.9 is affected; subsequent releases may not contain the insecure configuration, but this is not confirmed in the CVE data.

Because the service accepts connections on a publicly reachable port with no authentication, an attacker who can access the host or local network can invoke any RPC method. The EPSS score is not available, and the vulnerability is not listed in the CISA KEV catalog, but the combination of critical network‑level actions and command‑execution via popen() gives the flaw a high potential impact. The attack vector is local or network access to port 50052; the effects could include disabling DoS defenses, blackholing traffic, and executing arbitrary code on the server, thereby compromising the entire network.