# CVE-2021-35223: Execute Command Function Allows Remote Code Execution (RCE)Vulnerability

> Remote attackers can execute arbitrary commands via user string variables in audit events, leading to remote code execution on Serv-U File Server.

- **Severity:** High 8.5 (`CVSS:3.1/AV:N/AC:H/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 31 Aug 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-7822-xr7f-c5pr

## What is CVE-2021-35223?

CVE-2021-35223 is a high-severity command injection vulnerability in Solarwinds Serv-U, published on 31 Aug 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The Serv-U File Server allows for events such as user login failures to be audited by executing a command. This command can be supplied with parameters that can take the form of user string variables, allowing remote code execution.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2021-35223?

It affects 1 product.


Products: Solarwinds Serv-U.

## How do I fix CVE-2021-35223?

No fix has been published for CVE-2021-35223 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-35223 being exploited?

There is no known exploitation of CVE-2021-35223 in the wild and no public exploit code.

## Other vulnerabilities in Solarwinds Serv-U

- [CVE-2021-35211](https://insights.sbomify.com/CVE-2021-35211/): SolarWinds Serv-U Remote Code Execution (critical 9.0, exploited in the wild)
- [CVE-2024-28995](https://insights.sbomify.com/CVE-2024-28995/): SolarWinds Serv-U Path Traversal Vulnerability (high 8.6, exploited in the wild)
- [CVE-2026-28318](https://insights.sbomify.com/CVE-2026-28318/): SolarWinds Serv-U Uncontrolled Resource Consumption (high 7.5, exploited in the wild)
- [CVE-2021-35247](https://insights.sbomify.com/CVE-2021-35247/): SolarWinds Serv-U Improper Input Validation (medium 4.3, exploited in the wild)
- [CVE-2020-35481](https://insights.sbomify.com/CVE-2020-35481/): Code injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-35223 and fix it if it is affected.

What it is: CVE-2021-35223 is a high-severity command injection vulnerability in Solarwinds Serv-U, published on 31 Aug 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-35223 in the wild and no public exploit code.

Affected product: Solarwinds Serv-U. 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-2021-35223/ (Markdown: https://insights.sbomify.com/CVE-2021-35223/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-35223
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-35223
- OSV: https://osv.dev/vulnerability/CVE-2021-35223

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-35223/
Summaries are generated and may contain mistakes; the official description above is the record.