How severe is CVE-2021-21791?

CVE-2021-21791 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-21791 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21791?

CVE-2021-21791 affects Iobit Advanced Systemcare Ultimate. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21791?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-21791 published?

CVE-2021-21791 was published on 2021-08-05 and last updated on 2026-06-17.

CVE-2021-21791

CVE-2021-21791 is a medium-severity vulnerability in Iobit Advanced Systemcare Ultimate with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-782.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 2.1
EPSS exploit prediction: 0% (26th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-782
Affected product: Iobit Advanced Systemcare Ultimate
Published: 2021-08-05
Last modified: 2026-06-17

Description

An information disclosure vulnerability exists in the the way IOBit Advanced SystemCare Ultimate 14.2.0.220 driver handles Privileged I/O read requests. A specially crafted I/O request packet (IRP) can lead to privileged reads in the context of a driver which can result in sensitive information disclosure from the kernel. The IN instruction can read two bytes from the given I/O device, potentially leaking sensitive device data to unprivileged users.

Frequently asked questions

What is CVE-2021-21791?: An information disclosure vulnerability exists in the the way IOBit Advanced SystemCare Ultimate 14.2.0.220 driver handles Privileged I/O read requests. A specially crafted I/O request packet (IRP) can lead to privileged reads in the context of a driver which can result in sensitive information disclosure from the kernel. The IN instruction can read two bytes from the given I/O device, potentially leaking sensitive device data to unprivileged users.
How severe is CVE-2021-21791?: CVE-2021-21791 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-21791 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21791?: CVE-2021-21791 affects Iobit Advanced Systemcare Ultimate. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21791?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-21791 published?: CVE-2021-21791 was published on 2021-08-05 and last updated on 2026-06-17.

References

https://talosintelligence.com/vulnerability_reports/TALOS-2021-1255

Affected products (1)

cpe:2.3:a:iobit:advanced_systemcare_ultimate:14.2.0.220:*:*:*:*:*:*:*

More vulnerabilities in Iobit Advanced Systemcare Ultimate

CVE-2021-21789 — High (CVSS 8.8): A privilege escalation vulnerability exists in the way IOBit Advanced SystemCare Ultimate 14.2.0.220 driver handles…
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