What’s Vulnerable › Vulnerabilities

CVE-2021-21787

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-07-07 · updated 2026-06-17
• Weakness: CWE-782

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.

Affected products

• IObit Advanced SystemCare Utimate: 14.2.0.220

References

• https://talosintelligence.com/vulnerability_reports/TALOS-2021-1254
• https://talosintelligence.com/vulnerability_reports/TALOS-2021-1254

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