CVE-2026-48692

Publication date 26 May 2026

Last updated 27 May 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

8.1 · High

Score breakdown

Description

FastNetMon Community Edition through 1.2.9 exposes a gRPC API server on port 50052 with no authentication mechanism. The server is initialized with grpc::InsecureServerCredentials() (src/fastnetmon.cpp line 477) and a source code comment explicitly acknowledges 'Listen on the given address without any authentication mechanism.' None of the RPC methods in src/api.cpp (ExecuteBan, ExecuteUnBan, GetBanlist, GetTotalTrafficCounters, etc.) perform any credential verification. The ExecuteBan and ExecuteUnBan methods trigger security-critical actions: BGP route announcements that can blackhole network traffic, and execution of external notification scripts via popen(). An attacker with local network access can ban arbitrary IP addresses (causing denial of service to legitimate traffic), unban active attacks (disabling DDoS mitigation), and trigger script execution. There is also no role-based access control separating read-only monitoring from destructive administrative operations.

Status

Package Ubuntu Release Status
fastnetmon 26.04 LTS resolute
Needs evaluation
25.10 questing
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy Not in release
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation

Severity score breakdown

Parameter Value
Base score 8.1 · High
Attack vector Adjacent
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact None
Vector CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

References

Other references

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