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Fencer Vulns
high 8.8

CVE-2021-21786 json

A privilege escalation vulnerability exists in the IOCTL 0x9c406144 handling of IOBit Advanced SystemCare Ultimate 14.2.0.220.

published 2021-07-07 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-8958

cvss
8.8
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits
0
none known

Summary

A privilege escalation vulnerability exists in the IOCTL 0x9c406144 handling of IOBit Advanced SystemCare Ultimate 14.2.0.220. A specially crafted I/O request packet (IRP) can lead to increased privileges. An attacker can send a malicious IRP to trigger this vulnerability.

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • talosintelligence.com https://talosintelligence.com/vulnerability_reports/TALOS-2021-1253 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 8.8 CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • n/a Iobit

Classification

Weakness
  • CWE-782 Exposed IOCTL with Insufficient Access Control
  • CWE-269 Improper Privilege Management

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.