Is CVE-2021-21789 in the CISA KEV catalog?

No. CVE-2021-21789 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-21789?

CVE-2021-21789 has a CVSS v3 base score of 8.8 (HIGH).

What is the EPSS score for CVE-2021-21789?

CVE-2021-21789 has an EPSS score of 0.32% (24th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix or mitigate CVE-2021-21789?

No published fix for CVE-2021-21789 has been found yet. Check the linked vendor advisories for guidance as it becomes available.

CVE & CISA-KEV Catalog

CVE-2021-21789

HIGH

8.8

CVSS v3

NVD

Description

A privilege escalation vulnerability exists in the way IOBit Advanced SystemCare Ultimate 14.2.0.220 driver handles Privileged I/O write requests. During IOCTL 0x9c40a0e0, the first dword passed in the input buffer is the device port to write to and the dword at offset 4 is the value to write via the OUT instruction. A local attacker can send a malicious IRP to trigger this vulnerability.

CWE-782

How to fix

No published remediation has been found for this vulnerability's affected products yet.

Mitigation guidance may be in the linked vendor advisories in the References section below.

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CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeChanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Exploit Intelligence

0.32%probability of exploitation in 30 days

24thpercentile

Low risk: more likely to be exploited than 24% of all known CVEs.

References

Exploit1

talosintelligence.com

Related Vulnerabilities

Other CWE-782 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2021-21551	High	8.8	58%	KEV	-
CVE-2025-7771	Unscored	-	6.8%	-	-
CVE-2024-32370	Critical	9.8	1.0%	-	Fix
CVE-2024-30804	Critical	9.8	0.8%	-	-
CVE-2024-39251	Critical	10.0	0.7%	-	-
CVE-2024-33220	High	8.8	0.7%	-	-

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.