CVE-2021-21787

Name of the Vulnerable Software and Affected Versions IOBit Advanced SystemCare Ultimate version 14.2.0.220

Description A privilege escalation issue exists in the way the driver handles Privileged I/O write requests. During the IOCTL 0x9c40a0d8 operation, the first dword passed in the input buffer specifies the device port to write to, and the byte at offset 4 is the value to write via the OUT instruction. This OUT instruction can write one byte to the given I/O device port, potentially leading to escalated privileges of unprivileged users.

Recommendations For IOBit Advanced SystemCare Ultimate version 14.2.0.220, consider disabling the vulnerable driver handling Privileged I/O write requests until a patch is available. Restrict access to the IOCTL 0x9c40a0d8 operation to minimize the risk of exploitation. Avoid using the OUT instruction in the affected driver until the issue is resolved. At the moment, there is no information about a newer version that contains a fix for this vulnerability.