CVE-2026-48692

Unauthenticated gRPC API Allows Remote Code Execution and Denial of Service

Published May 26, 2026 CVSS 3.1 · 8.1 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:a:pavel-odintsov:fastnetmon:*:*:*:*:community:*:*:*
Type Values Removed Values Added
Title Unauthenticated gRPC API Allows Remote Code Execution and Denial of Service
Type Values Removed Values Added
Title Unauthenticated gRPC API Allows Remote Code Execution and DoS in FastNetMon Community Edition
Weaknesses CWE-284
CWE-73
CWE-863
Type Values Removed Values Added
Weaknesses CWE-306
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Unauthenticated gRPC API Allows Remote Code Execution and DoS in FastNetMon Community Edition
Weaknesses CWE-284
CWE-73
CWE-863
Type Values Removed Values Added
First Time appeared Pavel-odintsov
Pavel-odintsov fastnetmon
Vendors & Products Pavel-odintsov
Pavel-odintsov fastnetmon
Type Values Removed Values Added
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.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
May 26, 2026, 8:50 PM
Reserved
May 22, 2026, 12:00 AM
Status
Analyzed
Published
May 26, 2026, 4:16 PM
Modified
Jul 24, 2026, 11:10 AM