CVE-2021-42029

highpriority · track · 31EPSS 0.002 · 15 %ileDEEURUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.24% (15th) EPSS
CVSS 7.2 · high
Is it mine?
18 products
Check your exposure
Who says so?
6 sources
cnnvd · enisa_euvd · fstec_bdu · cisa_csaf_ot

EPSS · scored 2026-10-27

A vulnerability has been identified in SIMATIC STEP 7 (TIA Portal) V15 (All versions), SIMATIC STEP 7 (TIA Portal) V16 (All versions < V16 Update 5), SIMATIC STEP 7 (TIA Portal) V17 (All versions < V17 Update 2). An attacker could achieve privilege escalation on the web server of certain devices due to improper access control vulnerability in the engineering system software. The attacker needs to have direct access to the impacted web server.

01

remediations

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

A vendor fix is available.

  • FixedSIMATIC STEP 7 (TIA Portal) V16siemens_psirt

    Update to V16 Update 5 or later version

    https://support.industry.siemens.com/cs/gb/en/view/109775861/
  • FixedSIMATIC STEP 7 (TIA Portal) V17siemens_psirt

    Update to V17 Update 2 or later version

    https://support.industry.siemens.com/cs/gb/en/view/109784441/
  • FixedSIMATIC STEP 7 (TIA Portal) V16cisa_csaf_ot

    Update to V16 Update 5 or later version

    https://support.industry.siemens.com/cs/gb/en/view/109775861/
  • FixedSIMATIC STEP 7 (TIA Portal) V17cisa_csaf_ot

    Update to V17 Update 2 or later version

    https://support.industry.siemens.com/cs/gb/en/view/109784441/
  • MitigationSIMATIC STEP 7 (TIA Portal) V15siemens_psirt

    In case a new TIA-Portal version is not available, updating the web server's user configuration is not effective in this situation. Instead - the PLC must be deleted and reconfigured with a new project. WARNING: The PLC-program should be copied before deleting the PLC. Or - the original project (one that was not uploaded by a PLC) should be used to update the web server's user management and to download the changed configuration

  • MitigationSIMATIC STEP 7 (TIA Portal) V16siemens_psirt

    In case a new TIA-Portal version is not available, updating the web server's user configuration is not effective in this situation. Instead - the PLC must be deleted and reconfigured with a new project. WARNING: The PLC-program should be copied before deleting the PLC. Or - the original project (one that was not uploaded by a PLC) should be used to update the web server's user management and to download the changed configuration

  • MitigationSIMATIC STEP 7 (TIA Portal) V17siemens_psirt

    In case a new TIA-Portal version is not available, updating the web server's user configuration is not effective in this situation. Instead - the PLC must be deleted and reconfigured with a new project. WARNING: The PLC-program should be copied before deleting the PLC. Or - the original project (one that was not uploaded by a PLC) should be used to update the web server's user management and to download the changed configuration

  • MitigationSIMATIC STEP 7 (TIA Portal) V15cisa_csaf_ot

    In case a new TIA-Portal version is not available, updating the web server's user configuration is not effective in this situation. Instead - the PLC must be deleted and reconfigured with a new project. WARNING: The PLC-program should be copied before deleting the PLC. Or - the original project (one that was not uploaded by a PLC) should be used to update the web server's user management and to download the changed configuration

  • MitigationSIMATIC STEP 7 (TIA Portal) V16cisa_csaf_ot

    In case a new TIA-Portal version is not available, updating the web server's user configuration is not effective in this situation. Instead - the PLC must be deleted and reconfigured with a new project. WARNING: The PLC-program should be copied before deleting the PLC. Or - the original project (one that was not uploaded by a PLC) should be used to update the web server's user management and to download the changed configuration

  • MitigationSIMATIC STEP 7 (TIA Portal) V17cisa_csaf_ot

    In case a new TIA-Portal version is not available, updating the web server's user configuration is not effective in this situation. Instead - the PLC must be deleted and reconfigured with a new project. WARNING: The PLC-program should be copied before deleting the PLC. Or - the original project (one that was not uploaded by a PLC) should be used to update the web server's user management and to download the changed configuration

  • No fix plannedSIMATIC STEP 7 (TIA Portal) V15siemens_psirt

    Currently no fix is planned

  • No fix plannedSIMATIC STEP 7 (TIA Portal) V15cisa_csaf_ot

    Currently no fix is planned

02

cvss

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

7.8
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.4–7.8

v2.07.2highAV:L/AC:L/Au:N/C:C/I:C/A:Cprimary · NVD / NIST USexploitability 3.9 · impact 10
v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 5.9
v3.16.4mediumCVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:C/C:H/I:L/A:L/E:P/RL:O/RC:Csecondary · CISA US
v3.17.8highAV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v3.16.4mediumCVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:C/C:H/I:L/A:L/E:P/RL:O/RC:Csecondary · Siemens ProductCERT DE
v3.17.1highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-269USCWE-284USCWE-284USCWE-284USCWE-284US
04

affected products (18)

Products and version ranges known to be affected.

05

advisories (2)

Vendor and ecosystem advisories describing this.

  • SSA-350757SSA-350757: Improper Access Control Vulnerability in TIA Portal Affecting S7-1200 and S7-1500 CPUs Web Server (Incl. Related ET200 CPUs and SIPLUS variants)2022-04-12csaf · siemens_psirtDE

    An attacker could achieve privilege escalation on the web server of certain devices configured by SIMATIC STEP 7 (TIA Portal) due to incorrect handling of the webserver's user management configuration during downloading. This only affects the S7-1200 and S7-1500 CPUs' (incl. related ET200 CPUs and SIPLUS variants) web server, when activated. Siemens has released updates for several affected products and recommends to update to the latest versions. Siemens recommends specific countermeasures for products where updates are not, or not yet available.

  • ICSA-22-104-14Siemens SIMATIC STEP 7 (TIA Portal)2022-04-12icsa · cisa_csaf_otUS

    An attacker could achieve privilege escalation on the web server of certain devices configured by SIMATIC STEP 7 (TIA Portal) due to incorrect handling of the webserver's user management configuration during downloading. This only affects the S7-1200 and S7-1500 CPUs' (incl. related ET200 CPUs and SIPLUS variants) web server, when activated. Siemens has released updates for several affected products and recommends to update to the latest versions. Siemens recommends specific countermeasures for products where updates are not, or not yet available.

06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducisa_csaf_otnvdsiemens_psirtNVDCVE.orgMITRE
published 2022-04-12modified 2026-06-17
08

references (7)

External citations — patches, advisories, analysis.

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