# CVE-2021-40388: Privilege escalation in n/a

> An attacker can escalate privileges to NT SYSTEM authority by replacing a specially-crafted file in Advantech SQ Manager Server.

- **Severity:** High 8.8 (`CVSS:3.0/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:** 28 Jan 2022
- **Updated:** 15 Apr 2025
- **Also known as:** GHSA-h3w9-267q-297p

## What is CVE-2021-40388?

CVE-2021-40388 is a high-severity vulnerability in n/a, published on 28 Jan 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A privilege escalation vulnerability exists in Advantech SQ Manager Server 1.0.6. A specially-crafted file can be replaced in the system to escalate privileges to NT SYSTEM authority. An attacker can provide a malicious file to trigger this vulnerability.

Weakness: CWE-276 (Incorrect Default Permissions)

## Which versions are affected by CVE-2021-40388?

It affects 1 product.


Products: Advantech Sq Manager.

## How do I fix CVE-2021-40388?

No fix has been published for CVE-2021-40388 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-40388 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-40388 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-40388 and fix it if it is affected.

What it is: CVE-2021-40388 is a high-severity vulnerability in n/a, published on 28 Jan 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-40388 exists.

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-2021-40388/ (Markdown: https://insights.sbomify.com/CVE-2021-40388/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-40388
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-40388
- OSV: https://osv.dev/vulnerability/CVE-2021-40388

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-40388/
Summaries are generated and may contain mistakes; the official description above is the record.