# CVE-2021-43033: Command injection in n/a

> Remote attackers can execute arbitrary code as root on Kaseya Unitrends Backup Appliances due to untrusted input passed to system calls.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Dec 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-fw55-5674-qwvm

## What is CVE-2021-43033?

CVE-2021-43033 is a critical command injection vulnerability in n/a, published on 6 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. Multiple functions in the bpserverd daemon were vulnerable to arbitrary remote code execution as root. The vulnerability was caused by untrusted input (received by the server) being passed to system calls.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2021-43033?

It affects 1 product.


Products: Kaseya Unitrends Backup.

## How do I fix CVE-2021-43033?

No fix has been published for CVE-2021-43033 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-43033 being exploited?

There is no known exploitation of CVE-2021-43033 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2021-40386](https://insights.sbomify.com/CVE-2021-40386/): Code injection in n/a (critical 9.8)
- [CVE-2021-43035](https://insights.sbomify.com/CVE-2021-43035/): SQL injection in n/a (critical 9.8)
- [CVE-2021-43036](https://insights.sbomify.com/CVE-2021-43036/): Hardcoded credentials in n/a (critical 9.8)
- [CVE-2021-43042](https://insights.sbomify.com/CVE-2021-43042/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-43044](https://insights.sbomify.com/CVE-2021-43044/): Hardcoded credentials in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-43033 and fix it if it is affected.

What it is: CVE-2021-43033 is a critical command injection vulnerability in n/a, published on 6 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-43033 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-2021-43033/ (Markdown: https://insights.sbomify.com/CVE-2021-43033/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-43033
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-43033
- OSV: https://osv.dev/vulnerability/CVE-2021-43033

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-43033/
Summaries are generated and may contain mistakes; the official description above is the record.