CVE-2021-21786

Local privilege escalation via unconstrained PCI access

Published Jul 7, 2021 · Updated Aug 3, 2024

Privilege escalation in IObit Advanced SystemCare Ultimate 14.2.0.220 allows local users to gain elevated privileges via a crafted IRP. The Monitor_win10_x64.sys handler for IOCTL 0x9c406144 passes unconstrained user-controlled values to HalGetBusDataByOffset. Any local low-privileged user can access the world-readable and world-writable device object and alter PCI configuration or device registers to obtain higher privileges.

CVSS severity8.8
High
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in IObit Advanced SystemCare Ultimate 14.2.0.220 allows local users to gain elevated privileges via a crafted IRP. The Monitor_win10_x64.sys handler for IOCTL 0x9c406144 passes unconstrained user-controlled values to HalGetBusDataByOffset. Any local low-privileged user can access the world-readable and world-writable device object and alter PCI configuration or device registers to obtain higher privileges.

The record

CVE
CVE-2021-21786
Published
Jul 7, 2021
Updated
Aug 3, 2024
Vendor
IObit
Product
Advanced SystemCare Ultimate
Classifications
CWE-782, CWE-269, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 7, 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=IOBit Advanced SystemCare Ultimate 14.2.0.220

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

IObit · Advanced SystemCare Ultimateversion=IOBit Advanced SystemCare Ultimate 14.2.0.220

Published CVSS scores

7.8NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8Cisco TalosCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-782Exposed IOCTL with Insufficient Access Control
CWE-269Improper Privilege Management
T1068Exploitation for Privilege Escalation

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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