CVE-2021-20674

Code execution via installer DLL search order

Published Mar 12, 2021 · Updated Aug 3, 2024

Untrusted DLL search in the MagicConnect Client Program installer distributed before March 1, 2021 allows attackers to execute arbitrary code. The installer loads a specifically named DLL from its own folder without ensuring that the library is trusted. Exploitation requires a Remote Desktop session, a malicious DLL beside the installer, and user execution; code runs with that user's privileges.

CVSS severity7.0
High
EPSS probability0.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Untrusted DLL search in the MagicConnect Client Program installer distributed before March 1, 2021 allows attackers to execute arbitrary code. The installer loads a specifically named DLL from its own folder without ensuring that the library is trusted. Exploitation requires a Remote Desktop session, a malicious DLL beside the installer, and user execution; code runs with that user's privileges.

The record

CVE
CVE-2021-20674
Published
Mar 12, 2021
Updated
Aug 3, 2024
Vendor
NTT TechnoCross Corporation
Product
MagicConnect Client Program
Classifications
CWE-427, CAPEC-38, CAPEC-471, T1574.001
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 12, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=distributed before 2021 March 1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

NTT TechnoCross Corporation · MagicConnect Client Programversion=distributed before 2021 March 1

Published CVSS scores

5.1JPCERT/CCAV:N/AC:H/Au:N/C:P/I:P/A:P
7.0JPCERT/CCCVSS:3.0/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-427Uncontrolled Search Path Element
CAPEC-38Leveraging/Manipulating Configuration File Search Paths
CAPEC-471Search Order Hijacking
T1574.001DLL

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo