Siemens SCALANCE W780 and W740 Allocation of Resources Without Limits or Throttling (CVE-2021-25666)

medium Tenable OT Security Plugin ID 501057


The remote OT asset is affected by a vulnerability.


A vulnerability has been identified in SCALANCE W780 and W740 (IEEE 802.11n) family (All versions < V6.3). Sending specially crafted packets through the ARP protocol to an affected device could cause a partial denial-of-service, preventing the device to operate normally for a short period of time.

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The following text was originally created by the Cybersecurity and Infrastructure Security Agency (CISA). The original can be found at

Siemens recommends updating to the latest version:

- SCALANCE W780 and W740 (IEEE 802.11n) family: Update to v6.3 or later

As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends configuring the environment according to the Siemens operational guidelines for industrial security and following the recommendations in the product manuals.

For additional information, please refer to Siemens Security Advisory SSA-686152

See Also

Plugin Details

Severity: Medium

ID: 501057

Version: 1.4

Type: remote

Family: Tenable.ot

Published: 4/11/2023

Updated: 3/4/2024

Supported Sensors: Tenable OT Security

Risk Information


Risk Factor: Low

Score: 1.4


Risk Factor: Low

Base Score: 3.3

Temporal Score: 2.4

Vector: CVSS2#AV:A/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2021-25666


Risk Factor: Medium

Base Score: 4.3

Temporal Score: 3.8

Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:siemens:scalance_w740_series_firmware, cpe:/o:siemens:scalance_w780_series_firmware

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 2/9/2021

Vulnerability Publication Date: 2/9/2021

Reference Information

CVE: CVE-2021-25666

CWE: 770