CVE-2021-21787

Public Exploit

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 0x9c40a0d8, the first dword passed in the input buffer is the device port to write to and the byte at offset 4 is the value to write via the OUT instruction. The OUT instruction can write one byte to the given I/O device port, potentially leading to escalated privileges of unprivileged users.

Category

8.8
CVSS
Severity: High
CVSS 3.1 •
CVSS 3.0 •
CVSS 2.0 •
EPSS 0.14%
Third-Party Advisory talosintelligence.com
Affected: n/a Iobit
Published at:
Updated at:

References

Link Tags
https://talosintelligence.com/vulnerability_reports/TALOS-2021-1254 third party advisory exploit

Frequently Asked Questions

What is the severity of CVE-2021-21787?
CVE-2021-21787 has been scored as a high severity vulnerability.
How to fix CVE-2021-21787?
To fix CVE-2021-21787, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-21787 being actively exploited in the wild?
It is possible that CVE-2021-21787 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-21787?
CVE-2021-21787 affects n/a Iobit.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.