CVE intelligence and bounded remediation
CVE-2021-21787 — Iobit Advanced Systemcare Ultimate security vulnerability
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.
- Severity
- High
- CVSS
- 8.8 (3.1)
- Published
- 2021-07-07
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-782
Affected products
- iobit / advanced_systemcare_ultimate / 14.2.0.220
Matched remediation archetype
Privilege escalation and unsafe privilege management
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Map service accounts, operating-system identities, roles, capabilities, impersonation, set-user transitions, and administrative helper paths.
- Determine whether untrusted users or lower-privilege processes can reach the affected transition or modify inputs it trusts.
- Review file, socket, registry, device, job, container, and cloud-role permissions used before and after privilege changes.
Remediate safely
- Apply the supported fix and redesign privileged operations as a minimal, authenticated, allowlisted interface.
- Drop privileges before processing untrusted input, verify the drop succeeds, and remove unnecessary roles, capabilities, and write permissions.
- Validate ownership and permissions at time of use and add explicit lower-to-higher privilege boundary tests.
Authoritative sources
Complete CVE record and remediation plan
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