CVE-2021-21790Public exploit

Local device-data disclosure via exposed IOCTL

Published Aug 5, 2021 · Updated Aug 3, 2024

Information disclosure in the IObit Advanced SystemCare Ultimate 14.2.0.220 driver allows local users to read privileged device data. The world-accessible IOBIT_WinRing0_1_3_0 device accepts IOCTL 0x9c4060cc and uses the first input integer as an unchecked port operand for an IN-byte instruction. Any low-privileged local user able to open the driver device can retrieve one byte per request from an arbitrary I/O port, with no reported write or service-interruption impact.

CVSS severity6.5
Medium
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

Information disclosure in the IObit Advanced SystemCare Ultimate 14.2.0.220 driver allows local users to read privileged device data. The world-accessible IOBIT_WinRing0_1_3_0 device accepts IOCTL 0x9c4060cc and uses the first input integer as an unchecked port operand for an IN-byte instruction. Any low-privileged local user able to open the driver device can retrieve one byte per request from an arbitrary I/O port, with no reported write or service-interruption impact.

The record

CVE
CVE-2021-21790
Published
Aug 5, 2021
Updated
Aug 3, 2024
Vendor
IObit
Product
Advanced SystemCare Ultimate
Classifications
CWE-782, T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 5, 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

6.5Cisco TalosCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
2.1NVDAV:L/AC:L/Au:N/C:P/I:N/A:N
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-782Exposed IOCTL with Insufficient Access Control
T1005Data from Local System

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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