CVE-2021-42539Network attack vector

Account takeover via unchecked backup restoration

Published Oct 22, 2021 · Updated Sep 16, 2024

Missing authentication in Emerson WirelessHART Gateway 4.7.94 and earlier allows remote authenticated users to take over accounts. The system-backup restore path accepts a backup operation without validating that the requesting account has permission to restore privileged state. A low-privileged account and interaction with the restore workflow are required; successful exploitation permits account takeover and unauthorized settings changes.

CVSS severity8.8
High
EPSS probability0.79%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authentication in Emerson WirelessHART Gateway 4.7.94 and earlier allows remote authenticated users to take over accounts. The system-backup restore path accepts a backup operation without validating that the requesting account has permission to restore privileged state. A low-privileged account and interaction with the restore workflow are required; successful exploitation permits account takeover and unauthorized settings changes.

The record

CVE
CVE-2021-42539
Published
Oct 22, 2021
Updated
Sep 16, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-306
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.0ICS-CERTCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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