CVE-2021-33824Public exploitNetwork attack vector

Web service denial via incomplete HTTP requests

Published Jun 18, 2021 · Updated Aug 3, 2024

Resource exhaustion in Moxa MGate MB3180 Series firmware 2.2 and earlier allows remote attackers to interrupt the web service. The HTTP server retains incomplete request connections while waiting for completion, allowing enough slow connections to exhaust its resources. No authentication or user interaction is required; successful exploitation makes the web interface inaccessible.

CVSS severity7.5
High
EPSS probability1.93%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Moxa MGate MB3180 Series firmware 2.2 and earlier allows remote attackers to interrupt the web service. The HTTP server retains incomplete request connections while waiting for completion, allowing enough slow connections to exhaust its resources. No authentication or user interaction is required; successful exploitation makes the web interface inaccessible.

The record

CVE
CVE-2021-33824
Published
Jun 18, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-400, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 18, 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

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

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

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.003Endpoint Denial of Service: Application Exhaustion Flood

Public exploit references

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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