CVE-2021-25661

high

Published 2021-05-12 · Modified 2026-06-02

💬 Discuss on Community ✚ Propose mitigation

CVSS v3

7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v4 NEW

—

not yet in upstream

VIR risk

7.5

Description

A vulnerability has been identified in SIMATIC HMI Comfort Outdoor Panels V15 7\" & 15\" (incl. SIPLUS variants) (All versions < V15.1 Update 6), SIMATIC HMI Comfort Outdoor Panels V16 7\" & 15\" (incl. SIPLUS variants) (All versions < V16 Update 4), SIMATIC HMI Comfort Panels V15 4\" - 22\" (incl. SIPLUS variants) (All versions < V15.1 Update 6), SIMATIC HMI Comfort Panels V16 4\" - 22\" (incl. SIPLUS variants) (All versions < V16 Update 4), SIMATIC HMI KTP Mobile Panels V15 KTP400F, KTP700, KTP700F, KTP900 and KTP900F (All versions < V15.1 Update 6), SIMATIC HMI KTP Mobile Panels V16 KTP400F, KTP700, KTP700F, KTP900 and KTP900F (All versions < V16 Update 4), SIMATIC WinCC Runtime Advanced V15 (All versions < V15.1 Update 6), SIMATIC WinCC Runtime Advanced V16 (All versions < V16 Update 4). SmartVNC has an out-of-bounds memory access vulnerability that could be triggered on the client side when sending data from the server, which could result in a Denial-of-Service condition.

Predictions

Exploit likelihood

83%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

Application impact

Vendor	Product	Versions	Fixed
siemens	simatic_wincc_runtime_advanced	`{"endExcluding":"16"}`	`16`
siemens	simatic_wincc_runtime_advanced	`16`
siemens	simatic_hmi_comfort_outdoor_panels_7\"	`-`
siemens	simatic_hmi_comfort_outdoor_panels_15\"	`-`
siemens	simatic_hmi_comfort_panels_4\"	`-`
siemens	simatic_hmi_comfort_panels_22\"	`-`
siemens	simatic_hmi_ktp_mobile_panels_ktp400f	`-`
siemens	simatic_hmi_ktp_mobile_panels_ktp700	`-`
siemens	simatic_hmi_ktp_mobile_panels_ktp700f	`-`
siemens	simatic_hmi_ktp_mobile_panels_ktp900	`-`
siemens	simatic_hmi_ktp_mobile_panels_ktp900f	`-`
siemens	simatic_wincc_runtime_advanced	`{"endExcluding":"15.1"}`	`15.1`
siemens	simatic_wincc_runtime_advanced	`15.1`

References

CWEs

CWE-788

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.