Cyber Resilience

CVE-2021-25660

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 0.0046 64.4th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-25660 is a high-severity Access of Memory Location After End of Buffer (CWE-788) vulnerability in Siemens Simatic Hmi Comfort Outdoor Panels 15\" Firmware. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 35.6% 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 has an out-of-bounds memory access vulnerability that could be triggered on the server side when sending data from the client, 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 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
siemens
simatic wincc runtime advanced
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-119

Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.

addresses: CWE-119

Managed runtimes used by platform-independent applications (e.g., JVM, CLR) enforce memory safety, preventing most buffer overflows that require direct memory manipulation.

addresses: CWE-119

Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.

addresses: CWE-119

Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.

References