UgCS server before 6.2 contains an authentication bypass in the HCI protocol login handler (LoginHandler) exposed on TCP port 3334. When the user database contains exactly one user (the default single-operator installation), a LoginRequest with empty userLogin and userPassword fields is interpreted as \"use the only user\" rather than as invalid credentials, and the server returns a fully authenticated session. Because the service listens on all interfaces (0.0.0.0) without TLS by default, an unauthenticated remote attacker with network access to port 3334 can obtain an authenticated session without knowing any credential and then issue privileged commands, including commanding connected drones and uploading flight routes.
Advisories

No advisories yet.

Fixes

Solution

Upgrade to UgCS 6.2 or later, in which empty credentials are no longer accepted as a valid login.


Workaround

For deployments that cannot upgrade immediately: bind the HCI listener to 127.0.0.1, restrict TCP port 3334 with host and network firewall rules, and place the service behind an authenticated TLS transport.

History

Fri, 06 Nov 2026 22:00:00 +0000

Type Values Removed Values Added
Description UgCS server before 6.2 contains an authentication bypass in the HCI protocol login handler (LoginHandler) exposed on TCP port 3334. When the user database contains exactly one user (the default single-operator installation), a LoginRequest with empty userLogin and userPassword fields is interpreted as \"use the only user\" rather than as invalid credentials, and the server returns a fully authenticated session. Because the service listens on all interfaces (0.0.0.0) without TLS by default, an unauthenticated remote attacker with network access to port 3334 can obtain an authenticated session without knowing any credential and then issue privileged commands, including commanding connected drones and uploading flight routes.
Title UgCS server HCI authentication bypass with empty credentials
Weaknesses CWE-287
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: ENISA

Published:

Updated: 2026-11-06T21:41:49.884Z

Reserved: 2026-07-02T15:47:36.964Z

Link: CVE-2026-59104

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-11-06T22:17:59.043

Modified: 2026-11-06T22:17:59.043

Link: CVE-2026-59104

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses