MagicconnectApplication · Ntt Tx

CVE-2021-20674

HIGH · 7.8 CVSS v3.1 Published 2021-03-12
Fix available
A fix is available. Upgrade to 2021-03-01 or later.
See remediation →
81/100
Remediation priority · High
No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Untrusted search path vulnerability in Installer of MagicConnect Client program distributed before 2021 March 1 allows an attacker to gain privileges and via a Trojan horse DLL in an unspecified directory and to execute arbitrary code with the privilege of the user invoking the installer when a terminal is connected remotely using Remote desktop.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is a DLL hijacking vulnerability in the MagicConnect Client installer distributed before March 2021. The installer uses an untrusted search path, allowing it to load a malicious DLL placed by an attacker in an unspecified directory. When a user runs the installer during a Remote Desktop session, the Trojan horse DLL is loaded, enabling arbitrary code execution with the privileges of the user running the installer.

MitigationUpdate MagicConnect Client to a version released on or after March 1, 2021, which contains the corrected installer. Avoid running installers during remote desktop sessions as a compensating control until the update is applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
MagicconnectApplication
Affected:< 2021-03-01

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify MagicConnect Client installation
    Look for MagicConnect Client software on the system. Check Program Files directories or use the system's installed programs list (e.g., 'Programs and Features' in Control Panel or 'Get-WmiObject -Class Win32_Product' in PowerShell).
    Affected if MagicConnect Client is installed and the installer used was obtained before March 2021.
  2. Check installer file timestamp
    Locate the original MagicConnect installer file (.msi or setup.exe) that was used to install the client. Right-click the file, select Properties, and examine the 'Created' or 'Modified' date timestamp.
    Affected if The installer file was created or modified before March 1, 2021.
  3. Check for running Remote Desktop session
    Open Command Prompt or PowerShell and run 'query session' or 'Get-Process' commands to determine if the current session is a Remote Desktop (RDP) session. Alternatively, check the environment variable SESSIONNAME.
    Affected if The installer is being executed while the user is logged in via Remote Desktop services.
  4. Inspect installer directory for suspicious DLLs
    Examine the directory from which the MagicConnect installer was launched, as well as common DLL search path locations (system temp folders, working directory, system32). Look for unexpected or unfamiliar DLL files that could have been placed by an attacker.
    Affected if Unexpected DLL files exist in the installer's launch directory or in the DLL search path.

A system is affected if the MagicConnect Client installer was obtained and run before March 2021, particularly during a Remote Desktop session, and if unexpected DLL files are present in the installer directory or DLL search path.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to 2021-03-01 or later
Fixed in 2021-03-01
Interim mitigation

Update MagicConnect Client to a version released on or after March 1, 2021, which contains the corrected installer. Avoid running installers during remote desktop sessions as a compensating control until the update is applied.

Fix this in Magicconnect Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-20674 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-20674 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data