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Description

Tinycontrol devices such as tcPDU and LAN Controllers LK3.5, LK3.9 and LK4 have two separate authentication mechanisms - one solely for interface management and one for protecting all other server resources. When the latter is turned off (which is a default setting), an unauthenticated attacker on the local network can obtain usernames and encoded passwords for interface management portal by inspecting the HTTP response of the server when visiting the login page, which contains a JSON file with these details. Both normal and admin users credentials are exposed. This issue has been fixed in firmware versions: 1.36 (for tcPDU), 1.67 (for LK3.5 - hardware versions: 3.5, 3.6, 3.7 and 3.8), 1.75 (for LK3.9 - hardware version 3.9) and 1.38 (for LK4 - hardware version 4.0).

PUBLISHED Reserved 2025-10-08 | Published 2026-03-16 | Updated 2026-03-16 | Assigner CERT-PL




HIGH: 8.7CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Problem types

CWE-261 Weak Encoding for Password

CWE-201 Insertion of Sensitive Information Into Sent Data

Product status

Default status
unaffected

Any version before 1.67
affected

Default status
unaffected

Any version before 1.75
affected

Default status
unaffected

Any version before 1.38
affected

Default status
unaffected

Any version before 1.36
affected

Credits

Paweł Różański (Securitum.com) finder

References

cert.pl/en/posts/2026/03/CVE-2025-11500/ third-party-advisory

securitum.com/CVE-2025-11500 technical-description

tinycontrol.pl/en/archives/lan-controller-35/downloads/ release-notes

tinycontrol.pl/en/lk39/downloads/ release-notes

tinycontrol.pl/en/lk4/downloads/ release-notes

tinycontrol.pl/en/tcpdu/downloads/ release-notes

cve.org (CVE-2025-11500)

nvd.nist.gov (CVE-2025-11500)

Download JSON