VULNERABILITY INTELLIGENCE

CVE-2021-21787

CVSS score8.8 HIGH
EPSS probability0.34%
CISA KEVNot currently listed
Published2021-07-07
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

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.

Weakness classification

  • talos-cna@cisco.com: CWE-782
  • nvd@nist.gov: NVD-CWE-Other

Primary references