CVE-2021-21518

SYSTEM code execution via writable DLL search path

Published Mar 12, 2021 · Updated Sep 16, 2024

DLL injection in Dell SupportAssist Client Home 3.3.x through 3.7.x and Business 2.0.x through 2.2.x allows local users to gain SYSTEM. The SYSTEM-level DSAPI.exe process leaves a Costura-set, low-privilege-writable temporary directory in child-process DLL search paths without validating loaded libraries. A low-privileged local user can plant a missing DLL and launch a PC-Doctor task through the GUI or WebSocket IPC, causing the privileged module to load attacker code.

CVSS severity7.8
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

DLL injection in Dell SupportAssist Client Home 3.3.x through 3.7.x and Business 2.0.x through 2.2.x allows local users to gain SYSTEM. The SYSTEM-level DSAPI.exe process leaves a Costura-set, low-privilege-writable temporary directory in child-process DLL search paths without validating loaded libraries. A low-privileged local user can plant a missing DLL and launch a PC-Doctor task through the GUI or WebSocket IPC, causing the privileged module to load attacker code.

The record

CVE
CVE-2021-21518
Published
Mar 12, 2021
Updated
Sep 16, 2024
Vendor
Dell
Product
Dell SupportAssist Client
Classifications
CWE-427, T1574.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=unspecified <SACH 3.8, SACB 2.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Dell · Dell SupportAssist Clientversion=unspecified <SACH 3.8, SACB 2.3

Published CVSS scores

7.8DellCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2NVDAV:L/AC:L/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.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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

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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