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CVE Record

CVE-2021-33824: An issue was discovered on MOXA Mgate MB3180 Version 2.1 Build 18113012.

An issue was discovered on MOXA Mgate MB3180 Version 2.1 Build 18113012. Attackers can use slowhttptest tool to send incomplete HTTP request, which could make server keep waiting for the packet to finish the connection, until its resource exhausted. Then the web server is denial-of-service.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-33824 is a denial-of-service issue in the web server of a Moxa MGate MB3180 running Version 2.1 Build 18113012. A remote attacker could keep HTTP connections incomplete until server resources are exhausted, making the web interface unavailable. The sources do not show code execution, data theft, vendor severity, or confirmed active exploitation.

Executive priority

Prioritize if these gateways support critical operational connectivity or have exposed management interfaces. The issue appears availability-focused, not a data compromise path, but disruption to industrial gateways can still create operational impact.

Technical view

The CVE describes resource exhaustion caused by incomplete HTTP requests against the affected Moxa MGate MB3180 web server. The record references slowhttptest and a public PoC page, indicating the weakness is reproducible with known slow-HTTP testing techniques. No CVSS score, CWE, patch version, or vendor advisory details are provided in the supplied sources.

Likely exposure

Exposure is most likely where Moxa MGate MB3180 management web services are reachable from untrusted networks. Internet-exposed or flat OT networks would raise urgency. Devices isolated to trusted management networks have lower exposure, though local network attackers may still affect availability.

Exploitation context

The source bundle includes public testing and PoC references, but CISA KEV status is false and no cited source confirms active exploitation. Treat this as publicly known and potentially easy to reproduce, without claiming real-world exploitation.

Researcher notes

The affected scope is narrow in the CVE text: Moxa MGate MB3180 Version 2.1 Build 18113012. The supplied affected-product metadata is incomplete, and no official remediation text is included. Avoid expanding scope to related MGate models without vendor confirmation.

Mitigation direction

  • Check Moxa guidance for affected firmware and any fixed release.
  • Restrict the device web interface to trusted management networks.
  • Block public internet access to the management HTTP service.
  • Use firewall or access-control rules around OT management paths.
  • Monitor affected devices for web service unavailability or repeated connection exhaustion.

Validation and detection

  • Inventory Moxa MGate MB3180 devices and record firmware build numbers.
  • Identify whether Version 2.1 Build 18113012 is deployed.
  • Confirm management web interfaces are not internet-exposed.
  • Review network controls limiting access to the device web server.
  • Verify operational monitoring detects web management denial-of-service symptoms.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2021-33824 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
4Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.