CVE-2026-59104

UgCS server HCI authentication bypass with empty credentials

Published Nov 6, 2026 CVSS 4.0 · 9.3 Critical EPSS < 1% KEV · Not listed
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.

Remediation

Vendor Solution

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


Vendor 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.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Sphengineering
Sphengineering ugcs
Vendors & Products Sphengineering
Sphengineering ugcs
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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
ENISA
Published
Updated
Nov 10, 2026, 2:16 PM
Reserved
Jul 2, 2026, 3:47 PM
Status
Deferred
Published
Nov 6, 2026, 10:17 PM
Modified
Nov 12, 2026, 8:07 PM