CVE-2021-31340

mediumpriority · track · 30EPSS 0.010 · 62 %ileDEEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.99% (62nd) EPSS

CVSS 5 · medium

Is it mine?

131 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · cisa_csaf_ot · siemens_psirt

EPSS · scored 2026-10-28

A vulnerability has been identified in SIMATIC RF166C (All versions > V1.1 and < V1.3.2), SIMATIC RF185C (All versions > V1.1 and < V1.3.2), SIMATIC RF186C (All versions > V1.1 and < V1.3.2), SIMATIC RF186CI (All versions > V1.1 and < V1.3.2), SIMATIC RF188C (All versions > V1.1 and < V1.3.2), SIMATIC RF188CI (All versions > V1.1 and < V1.3.2), SIMATIC RF360R (All versions < V2.0), SIMATIC Reader RF610R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF610R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF610R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF615R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF615R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF615R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF650R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF650R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF650R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF650R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF680R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF680R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF680R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF680R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF685R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF685R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF685R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF685R FCC (All versions > V3.0 < V4.0). Affected devices do not properly handle large numbers of incoming connections. An attacker may leverage this to cause a Denial-of-Service situation.

remediations

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

A vendor fix is available.

FixedSIMATIC RF166Csiemens_psirt
Update to V1.3.2
https://support.industry.siemens.com/cs/ww/en/view/109768507
FixedSIMATIC RF185Csiemens_psirt
Update to V1.3.2
https://support.industry.siemens.com/cs/ww/en/view/109768507
FixedSIMATIC RF186Csiemens_psirt
Update to V1.3.2
https://support.industry.siemens.com/cs/ww/en/view/109768507
FixedSIMATIC RF186CIsiemens_psirt
Update to V1.3.2
https://support.industry.siemens.com/cs/ww/en/view/109768507
FixedSIMATIC RF188Csiemens_psirt
Update to V1.3.2
https://support.industry.siemens.com/cs/ww/en/view/109768507
FixedSIMATIC RF188CIsiemens_psirt
Update to V1.3.2
https://support.industry.siemens.com/cs/ww/en/view/109768507
FixedSIMATIC RF360Rsiemens_psirt
Update to V2.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808759
FixedSIMATIC Reader RF610R CMIITsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF610R ETSIsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF610R FCCsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF615R CMIITsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF615R ETSIsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF615R FCCsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF650R ARIBsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF650R CMIITsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF650R ETSIsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF650R FCCsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF680R ARIBsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF680R CMIITsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF680R ETSIsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF680R FCCsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF685R ARIBsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF685R CMIITsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF685R ETSIsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF685R FCCsiemens_psirt
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC RF166Ccisa_csaf_ot
Update to V1.3.2
https://support.industry.siemens.com/cs/ww/en/view/109768507
FixedSIMATIC RF185Ccisa_csaf_ot
Update to V1.3.2
https://support.industry.siemens.com/cs/ww/en/view/109768507
FixedSIMATIC RF186Ccisa_csaf_ot
Update to V1.3.2
https://support.industry.siemens.com/cs/ww/en/view/109768507
FixedSIMATIC RF186CIcisa_csaf_ot
Update to V1.3.2
https://support.industry.siemens.com/cs/ww/en/view/109768507
FixedSIMATIC RF188Ccisa_csaf_ot
Update to V1.3.2
https://support.industry.siemens.com/cs/ww/en/view/109768507
FixedSIMATIC RF188CIcisa_csaf_ot
Update to V1.3.2
https://support.industry.siemens.com/cs/ww/en/view/109768507
FixedSIMATIC RF360Rcisa_csaf_ot
Update to V2.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808759
FixedSIMATIC Reader RF610R CMIITcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF610R ETSIcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF610R FCCcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF615R CMIITcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF615R ETSIcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF615R FCCcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF650R ARIBcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF650R CMIITcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF650R ETSIcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF650R FCCcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF680R ARIBcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF680R CMIITcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF680R ETSIcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF680R FCCcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF685R ARIBcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF685R CMIITcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF685R ETSIcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
FixedSIMATIC Reader RF685R FCCcisa_csaf_ot
Update to V4.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109808361
MitigationSIMATIC RF166Csiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC RF185Csiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC RF186Csiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC RF186CIsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC RF188Csiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC RF188CIsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC RF360Rsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF610R CMIITsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF610R ETSIsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF610R FCCsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF615R CMIITsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF615R ETSIsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF615R FCCsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF650R ARIBsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF650R CMIITsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF650R ETSIsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF650R FCCsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF680R ARIBsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF680R CMIITsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF680R ETSIsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF680R FCCsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF685R ARIBsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF685R CMIITsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF685R ETSIsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF685R FCCsiemens_psirt
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC RF166Ccisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC RF185Ccisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC RF186Ccisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC RF186CIcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC RF188Ccisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC RF188CIcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC RF360Rcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF610R CMIITcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF610R ETSIcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF610R FCCcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF615R CMIITcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF615R ETSIcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF615R FCCcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF650R ARIBcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF650R CMIITcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF650R ETSIcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF650R FCCcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF680R ARIBcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF680R CMIITcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF680R ETSIcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF680R FCCcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF685R ARIBcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF685R CMIITcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF685R ETSIcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices
MitigationSIMATIC Reader RF685R FCCcisa_csaf_ot
Deactivate the OPC-UA feature of affected devices

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: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)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-400USprimaryCWE-400USCWE-400US

affected products (131)

Products and version ranges known to be affected.

SIMATIC RF166Call versionscisa_csaf_otUS
SIMATIC RF185Call versionscisa_csaf_otUS
SIMATIC RF186Call versionscisa_csaf_otUS
SIMATIC RF186CIall versionscisa_csaf_otUS
SIMATIC RF188Call versionscisa_csaf_otUS
SIMATIC RF188CIall versionscisa_csaf_otUS
SIMATIC RF360Rall versionscisa_csaf_otUS
SIMATIC Reader RF610R CMIITall versionscisa_csaf_otUS
SIMATIC Reader RF610R ETSIall versionscisa_csaf_otUS
SIMATIC Reader RF610R FCCall versionscisa_csaf_otUS
SIMATIC Reader RF615R CMIITall versionscisa_csaf_otUS
SIMATIC Reader RF615R ETSIall versionscisa_csaf_otUS
SIMATIC Reader RF615R FCCall versionscisa_csaf_otUS
SIMATIC Reader RF650R ARIBall versionscisa_csaf_otUS
SIMATIC Reader RF650R CMIITall versionscisa_csaf_otUS
SIMATIC Reader RF650R ETSIall versionscisa_csaf_otUS
SIMATIC Reader RF650R FCCall versionscisa_csaf_otUS
SIMATIC Reader RF680R ARIBall versionscisa_csaf_otUS
SIMATIC Reader RF680R CMIITall versionscisa_csaf_otUS
SIMATIC Reader RF680R ETSIall versionscisa_csaf_otUS

showing 20 of 131

advisories (2)

Vendor and ecosystem advisories describing this.

SSA-787292SSA-787292: Denial of Service Vulnerability in SIMATIC RFID Readers2021-06-08csaf · siemens_psirtDE
The latest updates for SIMATIC RF products fix a vulnerability that could allow an unauthorized attacker to crash the OPC UA service of the affected devices. Siemens has released updates for the affected products and recommends to update to the latest versions.
ICSA-21-159-13Siemens SIMATIC RFID (Update B)2021-06-08icsa · cisa_csaf_otUS
The latest updates for SIMATIC RF products fix a vulnerability that could allow an unauthorized attacker to crash the OPC UA service of the affected devices. Siemens has released updates for the affected products and recommends to update to the latest versions.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cisa_csaf_ot siemens_psirt NVD CVE.org MITRE

published 2021-06-08modified 2026-06-17

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references (6)

External citations — patches, advisories, analysis.

scry

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