CVE-2021-27383

mediumpriority · track · 31EPSS 0.018 · 78 %ileDEEUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
1.79% (78th) EPSS
CVSS 5 · medium
Is it mine?
112 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · cisa_csaf_ot · siemens_psirt

EPSS · scored 2026-10-27

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), SINAMICS GH150 (All versions), SINAMICS GL150 (with option X30) (All versions), SINAMICS GM150 (with option X30) (All versions), SINAMICS SH150 (All versions), SINAMICS SL150 (All versions), SINAMICS SM120 (All versions), SINAMICS SM150 (All versions), SINAMICS SM150i (All versions). SmartVNC has a heap allocation leak vulnerability in the server Tight encoder, which could result in a Denial-of-Service condition.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

  • FixedSIMATIC HMI Comfort Outdoor Panels V15 7" & 15" (incl. SIPLUS variants)siemens_psirt

    Update SIMATIC WinCC (TIA Portal) to V15.1 Update 6, and then update panel to V15.1 Update 6

    https://support.industry.siemens.com/cs/ww/en/view/109763890/
  • FixedSIMATIC HMI Comfort Outdoor Panels V16 7" & 15" (incl. SIPLUS variants)siemens_psirt

    Update SIMATIC WinCC (TIA Portal) to V16 Update 4 or later version, and then update panel to V16 Update 4 or later version

    https://support.industry.siemens.com/cs/ww/en/view/109775861/
  • FixedSIMATIC HMI Comfort Panels V15 4" - 22" (incl. SIPLUS variants)siemens_psirt

    Update SIMATIC WinCC (TIA Portal) to V15.1 Update 6, and then update panel to V15.1 Update 6

    https://support.industry.siemens.com/cs/ww/en/view/109763890/
  • FixedSIMATIC HMI Comfort Panels V16 4" - 22" (incl. SIPLUS variants)siemens_psirt

    Update SIMATIC WinCC (TIA Portal) to V16 Update 4 or later version, and then update panel to V16 Update 4 or later version

    https://support.industry.siemens.com/cs/ww/en/view/109775861/
  • FixedSIMATIC HMI KTP Mobile Panels V15 KTP400F, KTP700, KTP700F, KTP900 and KTP900Fsiemens_psirt

    Update SIMATIC WinCC (TIA Portal) to V15.1 Update 6, and then update panel to V15.1 Update 6

    https://support.industry.siemens.com/cs/ww/en/view/109763890/
  • FixedSIMATIC HMI KTP Mobile Panels V16 KTP400F, KTP700, KTP700F, KTP900 and KTP900Fsiemens_psirt

    Update SIMATIC WinCC (TIA Portal) to V16 Update 4 or later version, and then update panel to V16 Update 4 or later version

    https://support.industry.siemens.com/cs/ww/en/view/109775861/
  • FixedSIMATIC WinCC Runtime Advanced V15siemens_psirt

    Update to V15.1 Update 6

    https://support.industry.siemens.com/cs/ww/en/view/109763890/
  • FixedSIMATIC WinCC Runtime Advanced V16siemens_psirt

    Update to V16 Update 4 or later version

    https://support.industry.siemens.com/cs/ww/en/view/109776018/
  • FixedSIMATIC HMI Comfort Outdoor Panels V15 7" & 15" (incl. SIPLUS variants)cisa_csaf_ot

    Update SIMATIC WinCC (TIA Portal) to V15.1 Update 6, and then update panel to V15.1 Update 6

    https://support.industry.siemens.com/cs/ww/en/view/109763890/
  • FixedSIMATIC HMI Comfort Outdoor Panels V16 7" & 15" (incl. SIPLUS variants)cisa_csaf_ot

    Update SIMATIC WinCC (TIA Portal) to V16 Update 4 or later version, and then update panel to V16 Update 4 or later version

    https://support.industry.siemens.com/cs/ww/en/view/109775861/
  • FixedSIMATIC HMI Comfort Panels V15 4" - 22" (incl. SIPLUS variants)cisa_csaf_ot

    Update SIMATIC WinCC (TIA Portal) to V15.1 Update 6, and then update panel to V15.1 Update 6

    https://support.industry.siemens.com/cs/ww/en/view/109763890/
  • FixedSIMATIC HMI Comfort Panels V16 4" - 22" (incl. SIPLUS variants)cisa_csaf_ot

    Update SIMATIC WinCC (TIA Portal) to V16 Update 4 or later version, and then update panel to V16 Update 4 or later version

    https://support.industry.siemens.com/cs/ww/en/view/109775861/
  • FixedSIMATIC HMI KTP Mobile Panels V15 KTP400F, KTP700, KTP700F, KTP900 and KTP900Fcisa_csaf_ot

    Update SIMATIC WinCC (TIA Portal) to V15.1 Update 6, and then update panel to V15.1 Update 6

    https://support.industry.siemens.com/cs/ww/en/view/109763890/
  • FixedSIMATIC HMI KTP Mobile Panels V16 KTP400F, KTP700, KTP700F, KTP900 and KTP900Fcisa_csaf_ot

    Update SIMATIC WinCC (TIA Portal) to V16 Update 4 or later version, and then update panel to V16 Update 4 or later version

    https://support.industry.siemens.com/cs/ww/en/view/109775861/
  • FixedSIMATIC WinCC Runtime Advanced V15cisa_csaf_ot

    Update to V15.1 Update 6

    https://support.industry.siemens.com/cs/ww/en/view/109763890/
  • FixedSIMATIC WinCC Runtime Advanced V16cisa_csaf_ot

    Update to V16 Update 4 or later version

    https://support.industry.siemens.com/cs/ww/en/view/109776018/
  • MitigationSINAMICS GH150siemens_psirt

    As only SIMATIC HMI image versions < V16 Update 4 are affected, please update the HMI Panel image as included in your installation of SINAMICS GH150 to V16 Update 4 or later version

  • MitigationSINAMICS GL150 (with option X30)siemens_psirt

    As only SIMATIC HMI image versions < V16 Update 4 are affected, please update the HMI Panel image as included in your installation of SINAMICS GL150 (with option X30) to V16 Update 4 or later version

  • MitigationSINAMICS GM150 (with option X30)siemens_psirt

    As only SIMATIC HMI image versions < V16 Update 4 are affected, please update the HMI Panel image as included in your installation of SINAMICS GM150 (with option X30) to V16 Update 4 or later version

  • MitigationSINAMICS SH150siemens_psirt

    As only SIMATIC HMI image versions < V16 Update 4 are affected, please update the HMI Panel image as included in your installation of SINAMICS SH150 to V16 Update 4 or later version

  • MitigationSINAMICS SL150siemens_psirt

    As only SIMATIC HMI image versions < V15 SP1 Update 6 are affected, please update the HMI Panel image as included in your installation of SINAMICS SL150 to V15 SP1 Update 6 or later version

  • MitigationSINAMICS SM120siemens_psirt

    As only SIMATIC HMI image versions < V16 Update 4 are affected, please update the HMI Panel image as included in your installation of SINAMICS SM120 to V16 Update 4 or later version

  • MitigationSINAMICS SM150siemens_psirt

    As only SIMATIC HMI image versions < V15 SP1 Update 6 are affected, please update the HMI Panel image as included in your installation of SINAMICS SM150 to V15 SP1 Update 6 or later version

  • MitigationSINAMICS SM150isiemens_psirt

    As only SIMATIC HMI image versions < V15 SP1 Update 6 are affected, please update the HMI Panel image as included in your installation of SINAMICS SM150i to V15 SP1 Update 6 or later version

  • MitigationSIMATIC HMI Comfort Outdoor Panels V15 7" & 15" (incl. SIPLUS variants)siemens_psirt

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC HMI Comfort Outdoor Panels V16 7" & 15" (incl. SIPLUS variants)siemens_psirt

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC HMI Comfort Panels V15 4" - 22" (incl. SIPLUS variants)siemens_psirt

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC HMI Comfort Panels V16 4" - 22" (incl. SIPLUS variants)siemens_psirt

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC HMI KTP Mobile Panels V15 KTP400F, KTP700, KTP700F, KTP900 and KTP900Fsiemens_psirt

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC HMI KTP Mobile Panels V16 KTP400F, KTP700, KTP700F, KTP900 and KTP900Fsiemens_psirt

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC WinCC Runtime Advanced V15siemens_psirt

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC WinCC Runtime Advanced V16siemens_psirt

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSINAMICS GH150cisa_csaf_ot

    As only SIMATIC HMI image versions < V16 Update 4 are affected, please update the HMI Panel image as included in your installation of SINAMICS GH150 to V16 Update 4 or later version

  • MitigationSINAMICS GL150 (with option X30)cisa_csaf_ot

    As only SIMATIC HMI image versions < V16 Update 4 are affected, please update the HMI Panel image as included in your installation of SINAMICS GL150 (with option X30) to V16 Update 4 or later version

  • MitigationSINAMICS GM150 (with option X30)cisa_csaf_ot

    As only SIMATIC HMI image versions < V16 Update 4 are affected, please update the HMI Panel image as included in your installation of SINAMICS GM150 (with option X30) to V16 Update 4 or later version

  • MitigationSINAMICS SH150cisa_csaf_ot

    As only SIMATIC HMI image versions < V16 Update 4 are affected, please update the HMI Panel image as included in your installation of SINAMICS SH150 to V16 Update 4 or later version

  • MitigationSINAMICS SL150cisa_csaf_ot

    As only SIMATIC HMI image versions < V15 SP1 Update 6 are affected, please update the HMI Panel image as included in your installation of SINAMICS SL150 to V15 SP1 Update 6 or later version

  • MitigationSINAMICS SM120cisa_csaf_ot

    As only SIMATIC HMI image versions < V16 Update 4 are affected, please update the HMI Panel image as included in your installation of SINAMICS SM120 to V16 Update 4 or later version

  • MitigationSINAMICS SM150cisa_csaf_ot

    As only SIMATIC HMI image versions < V15 SP1 Update 6 are affected, please update the HMI Panel image as included in your installation of SINAMICS SM150 to V15 SP1 Update 6 or later version

  • MitigationSINAMICS SM150icisa_csaf_ot

    As only SIMATIC HMI image versions < V15 SP1 Update 6 are affected, please update the HMI Panel image as included in your installation of SINAMICS SM150i to V15 SP1 Update 6 or later version

  • MitigationSIMATIC HMI Comfort Outdoor Panels V15 7" & 15" (incl. SIPLUS variants)cisa_csaf_ot

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC HMI Comfort Outdoor Panels V16 7" & 15" (incl. SIPLUS variants)cisa_csaf_ot

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC HMI Comfort Panels V15 4" - 22" (incl. SIPLUS variants)cisa_csaf_ot

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC HMI Comfort Panels V16 4" - 22" (incl. SIPLUS variants)cisa_csaf_ot

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC HMI KTP Mobile Panels V15 KTP400F, KTP700, KTP700F, KTP900 and KTP900Fcisa_csaf_ot

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC HMI KTP Mobile Panels V16 KTP400F, KTP700, KTP700F, KTP900 and KTP900Fcisa_csaf_ot

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC WinCC Runtime Advanced V15cisa_csaf_ot

    Restrict access to port 5900/tcp to trusted IP addresses only

  • MitigationSIMATIC WinCC Runtime Advanced V16cisa_csaf_ot

    Restrict access to port 5900/tcp to trusted IP addresses only

  • No fix availableSINAMICS GH150siemens_psirt

    Currently no remediation is available

  • No fix availableSINAMICS GL150 (with option X30)siemens_psirt

    Currently no remediation is available

  • No fix availableSINAMICS GM150 (with option X30)siemens_psirt

    Currently no remediation is available

  • No fix availableSINAMICS SH150siemens_psirt

    Currently no remediation is available

  • No fix availableSINAMICS SL150siemens_psirt

    Currently no remediation is available

  • No fix availableSINAMICS SM120siemens_psirt

    Currently no remediation is available

  • No fix availableSINAMICS SM150siemens_psirt

    Currently no remediation is available

  • No fix availableSINAMICS SM150isiemens_psirt

    Currently no remediation is available

  • No fix availableSINAMICS GH150cisa_csaf_ot

    Currently no remediation is available

  • No fix availableSINAMICS GL150 (with option X30)cisa_csaf_ot

    Currently no remediation is available

  • No fix availableSINAMICS GM150 (with option X30)cisa_csaf_ot

    Currently no remediation is available

  • No fix availableSINAMICS SH150cisa_csaf_ot

    Currently no remediation is available

  • No fix availableSINAMICS SL150cisa_csaf_ot

    Currently no remediation is available

  • No fix availableSINAMICS SM120cisa_csaf_ot

    Currently no remediation is available

  • No fix availableSINAMICS SM150cisa_csaf_ot

    Currently no remediation is available

  • No fix availableSINAMICS SM150icisa_csaf_ot

    Currently no remediation is available

02

cvss

Technical severity, 0–10. One row per scoring source.

7.5
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 10 · impact 2.9
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:Csecondary · CISA US
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondaryexploitability 3.9 · impact 3.6
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:Csecondary · Siemens ProductCERT DE
v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-770USCWE-770USCWE-770US
05

affected products (112)

Products and version ranges known to be affected.

showing 20 of 112
06

advisories (4)

Vendor and ecosystem advisories describing this.

  • SSA-286838SSA-286838: Multiple Vulnerabilities in SINAMICS Medium Voltage Products2021-05-11csaf · siemens_psirtDE

    SINAMICS medium voltage products, with Sm@rtServer enabled on SIMATIC comfort HMI Panels, are affected by multiple vulnerabilities that could allow an attacker, under certain conditions, to gain full remote access to the HMI. Note that by default Sm@rtServer is disabled, but it can be enabled by the system integrator on request. Siemens has released updates for the affected products, and recommends to update them to the latest version.

  • SSA-538778SSA-538778: SmartVNC Vulnerabilities in SIMATIC HMI/WinCC Products2021-05-11csaf · siemens_psirtDE

    Multiple SmartVNC vulnerabilities in the affected products listed below could allow remote code execution and Denial-of-Service attacks under certain conditions. Siemens has released updates for the affected products and recommends to update to the latest version.

  • ICSA-21-131-04Siemens SINAMICS Medium Voltage Products Remote Access (Update B)2021-05-11icsa · cisa_csaf_otUS

    SINAMICS medium voltage products, with Sm@rtServer enabled on SIMATIC comfort HMI Panels, are affected by multiple vulnerabilities that could allow an attacker, under certain conditions, to gain full remote access to the HMI. Note that by default Sm@rtServer is disabled, but it can be enabled by the system integrator on request. Siemens has released updates for the affected products, and recommends to update them to the latest version.

  • ICSA-21-131-12Siemens SIMATIC SmartVNC HMI WinCC Products (Update B)2021-05-11icsa · cisa_csaf_otUS

    Multiple SmartVNC vulnerabilities in the affected products listed below could allow remote code execution and Denial-of-Service attacks under certain conditions. Siemens has released updates for the affected products and recommends to update to the latest version.

07

also known as (3)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdcisa_csaf_otsiemens_psirtNVDCVE.orgMITRE
published 2021-05-12modified 2026-06-17
09

references (12)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan