CVE-2021-20616

Privilege escalation via DLL preloading

Published Jan 13, 2021 · Updated Aug 3, 2024

SKYSEA Client View 1.020.05b through 16.001.01g allows local users to gain privileges via a Trojan DLL loaded by its installer. The installer searches an unspecified directory and insecurely loads a DLL supplied by an attacker, enabling arbitrary code execution in the installer's security context. Exploitation requires local access and user interaction to run installation or uninstallation; the vendor reports no remote execution path.

CVSS severity7.8
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SKYSEA Client View 1.020.05b through 16.001.01g allows local users to gain privileges via a Trojan DLL loaded by its installer. The installer searches an unspecified directory and insecurely loads a DLL supplied by an attacker, enabling arbitrary code execution in the installer's security context. Exploitation requires local access and user interaction to run installation or uninstallation; the vendor reports no remote execution path.

The record

CVE
CVE-2021-20616
Published
Jan 13, 2021
Updated
Aug 3, 2024
Vendor
Sky Co., Ltd.
Product
SKYSEA Client View
Classifications
CWE-427, T1574.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 13, 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?

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

  1. Affected versionversion=Ver.1.020.05b to Ver.16.001.01g

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Sky Co., Ltd. · SKYSEA Client Viewversion=Ver.1.020.05b to Ver.16.001.01g

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
4.4NVDAV:L/AC:M/Au:N/C:P/I:P/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.

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-427DLL Search Order Hijacking
T1574.002DLL Side-Loading

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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