CVE-2021-20047Public exploit

User-context code execution via user-writable DLL search

Published Dec 8, 2021 · Updated Aug 3, 2024

DLL search-order hijacking in SonicWall Global VPN Client 4.10.6 and earlier allows local users to execute code on Windows. The client searches for missing EPASpoof.dll in user-writable AppData paths and loads an attacker-planted copy when the application starts. Execution requires local write access and a subsequent client launch, and the payload runs in the launching user's context.

CVSS severity7.8
High
EPSS probability0.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

DLL search-order hijacking in SonicWall Global VPN Client 4.10.6 and earlier allows local users to execute code on Windows. The client searches for missing EPASpoof.dll in user-writable AppData paths and loads an attacker-planted copy when the application starts. Execution requires local write access and a subsequent client launch, and the payload runs in the launching user's context.

The record

CVE
CVE-2021-20047
Published
Dec 8, 2021
Updated
Aug 3, 2024
Vendor
SonicWall
Product
Global VPN Client
Classifications
CWE-427, T1574.001
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 8, 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=Global VPN Client 4.10.6 and earlier

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

SonicWall · Global VPN Clientversion=Global VPN Client 4.10.6 and earlier

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.9NVDAV:L/AC:M/Au:N/C:C/I:C/A:C

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.

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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 exploitPublished

Weakness, pattern, technique

CWE-427Uncontrolled Search Path Element
T1574.001Hijack Execution Flow: DLL Search Order Hijacking

Public exploit references

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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