CVE-2021-25847Network attack vector

Unauthenticated data disclosure via unchecked TLV length

Published May 10, 2021 · Updated Aug 3, 2024

Out-of-bounds read in Moxa VPort 06EC-2V firmware 1.1 and earlier allows remote attackers to disclose data via crafted LLDP packets. The userdisk/vport_lldpd daemon uses an unvalidated LLDP-MED TLV length to control a loop, causing reads beyond the supplied element. No authentication or user interaction is required, and successful processing can expose sensitive information or interrupt the device.

CVSS severity9.1
Critical
EPSS probability1.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Moxa VPort 06EC-2V firmware 1.1 and earlier allows remote attackers to disclose data via crafted LLDP packets. The userdisk/vport_lldpd daemon uses an unvalidated LLDP-MED TLV length to control a loop, causing reads beyond the supplied element. No authentication or user interaction is required, and successful processing can expose sensitive information or interrupt the device.

The record

CVE
CVE-2021-25847
Published
May 10, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-125
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 10, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.1INCIBE-CERTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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