# CVE-2021-21791: Information disclosure in IOBit

> A vulnerability in IOBit Advanced SystemCare Ultimate allows unprivileged users to read sensitive kernel data via crafted I/O requests.

- **Severity:** Medium 6.5 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Aug 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-8pwv-2qmp-97q9

## What is CVE-2021-21791?

CVE-2021-21791 is a medium-severity vulnerability in IOBit, published on 5 Aug 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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.

Weakness: CWE-782 (Exposed IOCTL with Insufficient Access Control)

## Which versions are affected by CVE-2021-21791?

It affects 1 product.


Products: Iobit Advanced Systemcare Ultimate.

## How do I fix CVE-2021-21791?

No fix has been published for CVE-2021-21791 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-21791 being exploited?

There is no known exploitation of CVE-2021-21791 in the wild and no public exploit code.

## Other vulnerabilities in IOBit

- [CVE-2021-21786](https://insights.sbomify.com/CVE-2021-21786/): Privilege escalation in Iobit (high 8.8)
- [CVE-2021-21787](https://insights.sbomify.com/CVE-2021-21787/): Privilege escalation in Iobit (high 8.8)
- [CVE-2021-21788](https://insights.sbomify.com/CVE-2021-21788/): Privilege escalation in Iobit (high 8.8)
- [CVE-2021-21789](https://insights.sbomify.com/CVE-2021-21789/): Privilege escalation in Iobit (high 8.8)
- [CVE-2018-9040](https://insights.sbomify.com/CVE-2018-9040/): Denial of service in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21791 and fix it if it is affected.

What it is: CVE-2021-21791 is a medium-severity vulnerability in IOBit, published on 5 Aug 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-21791 in the wild and no public exploit code.

Affected product: IOBit. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-21791/ (Markdown: https://insights.sbomify.com/CVE-2021-21791/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21791
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21791
- OSV: https://osv.dev/vulnerability/CVE-2021-21791

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21791/
Summaries are generated and may contain mistakes; the official description above is the record.