# CVE-2020-28921: Privilege escalation in n/a

> Low-privilege users can exploit the PCADRVX64.SYS kernel driver to read/write arbitrary MSRs, leading to Ring-0 code execution and privilege escalation.

- **Severity:** High 8.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **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:** 27 Nov 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-pfq8-gmrx-7h6x

## What is CVE-2020-28921?

CVE-2020-28921 is a high-severity vulnerability in n/a, published on 27 Nov 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An issue was discovered in Devid Espenschied PC Analyser through 4.10. The PCADRVX64.SYS kernel driver exposes IOCTL functionality that allows low-privilege users to read and write to arbitrary Model Specific Registers (MSRs). This could lead to arbitrary Ring-0 code execution and escalation of privileges.

## Which versions are affected by CVE-2020-28921?

It affects 1 product.


Products: Pcanalyser Pc Analyser.

## How do I fix CVE-2020-28921?

No fix has been published for CVE-2020-28921 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-28921 being exploited?

There is no known exploitation of CVE-2020-28921 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2020-28922](https://insights.sbomify.com/CVE-2020-28922/): Privilege escalation in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-28921 and fix it if it is affected.

What it is: CVE-2020-28921 is a high-severity vulnerability in n/a, published on 27 Nov 2020. 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-2020-28921 in the wild and no public exploit code.

Affected product: n/a. 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-2020-28921/ (Markdown: https://insights.sbomify.com/CVE-2020-28921/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-28921
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-28921
- OSV: https://osv.dev/vulnerability/CVE-2020-28921

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-28921/
Summaries are generated and may contain mistakes; the official description above is the record.