Cyber Resilience

CVE-2021-25662

HighUpdated

Published: 12 May 2021

Published
12 May 2021
Modified
02 June 2026
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0074 73.4th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-25662 is a high-severity Improper Handling of Exceptional Conditions (CWE-755) vulnerability in Siemens Simatic Hmi Comfort Outdoor Panels 15\" Firmware. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 26.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

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 client fails to handle an exception properly if the program execution process is modified after sending a packet from the server, which could result in a Denial-of-Service condition.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

siemens
simatic wincc runtime advanced
15.1, 16 · ≤ 16 · ≤ 15.1
siemens
simatic hmi comfort outdoor panels 7\" firmware
15.1, 16 · ≤ 16 · ≤ 15.1
siemens
simatic hmi comfort outdoor panels 15\" firmware
15.1, 16 · ≤ 16 · ≤ 15.1
siemens
simatic hmi comfort panels 4\" firmware
15.1, 16 · ≤ 16 · ≤ 15.1
siemens
simatic hmi comfort panels 22\" firmware
15.1, 16 · ≤ 16 · ≤ 15.1
siemens
simatic hmi ktp mobile panels ktp400f firmware
15.1, 16 · ≤ 16 · ≤ 15.1
siemens
simatic hmi ktp mobile panels ktp700 firmware
15.1, 16 · ≤ 16 · ≤ 15.1
siemens
simatic hmi ktp mobile panels ktp700f firmware
15.1, 16 · ≤ 16 · ≤ 15.1
siemens
simatic hmi ktp mobile panels ktp900 firmware
15.1, 16 · ≤ 16 · ≤ 15.1
siemens
simatic hmi ktp mobile panels ktp900f firmware
15.1, 16 · ≤ 16 · ≤ 15.1

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-755

Provides defined handling (alert and additional actions) for the exceptional condition of audit logging failure.

addresses: CWE-755

Supplies a concrete handling action (safe mode) for exceptional conditions, mitigating risks from improper or absent handling that could allow continued attacks.

addresses: CWE-755

By preparing users for contingency scenarios, the control promotes proper handling of exceptional conditions instead of default or unsafe behaviors.

addresses: CWE-755

An updated contingency plan defines current actions for exceptional conditions, reducing the window for attackers to exploit improper handling leading to system failure.

addresses: CWE-755

Procedures ensure proper handling of exceptional conditions to support effective incident response.

addresses: CWE-755

Incident response testing confirms proper handling of exceptional conditions to limit exploit impact.

addresses: CWE-755

Gives users guidance on incident handling, reducing improper handling of exceptional conditions that could stem from exploited weaknesses.

addresses: CWE-755

Enforces structured response to exceptional conditions so the system cannot remain in an unsafe state.

References