CVE-2020-5546

Malware execution via crafted TCP packet

Published Mar 16, 2020 · Updated Aug 4, 2024

Argument injection in Mitsubishi Electric MELQIC IU1-1M20-D firmware 1.0.7 and earlier allows attackers to execute malware via a TCP packet. The TCP/IP function treats unneutralized argument delimiters from packet data as command arguments; no finer code locus is public. The attacker must share the target's network segment, and the same flaw can also stop the appliance's network functions.

CVSS severity8.8
High
EPSS probability0.90%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Argument injection in Mitsubishi Electric MELQIC IU1-1M20-D firmware 1.0.7 and earlier allows attackers to execute malware via a TCP packet. The TCP/IP function treats unneutralized argument delimiters from packet data as command arguments; no finer code locus is public. The attacker must share the target's network segment, and the same flaw can also stop the appliance's network functions.

The record

CVE
CVE-2020-5546
Published
Mar 16, 2020
Updated
Aug 4, 2024
Vendor
Mitsubishi Electric Corporation
Product
MELQIC IU1 Series
Classifications
CWE-88, T0866
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 16, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=IU1-1M20-D firmware version 1.0.7 and earlier

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Mitsubishi Electric Corporation · MELQIC IU1 Seriesversion=IU1-1M20-D firmware version 1.0.7 and earlier

Published CVSS scores

5.8NIST NVDAV:A/AC:L/Au:N/C:P/I:P/A:P
8.8NIST NVDCVSS:3.1/AV:A/AC:L/PR:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-88Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
T0866Exploitation of Remote Services

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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