# CVE-2021-3277: File upload in n/a

> Authenticated administrators can upload arbitrary PHP files via improper validation in the custom-includes component, leading to remote code execution.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Jun 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-xj6h-r3q8-7cmf

## What is CVE-2021-3277?

CVE-2021-3277 is a high-severity vulnerability in Nagios Nagios Xi, published on 7 Jun 2021. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Nagios XI 5.7.5 and earlier allows authenticated admins to upload arbitrary files due to improper validation of the rename functionality in custom-includes component, which leads to remote code execution by uploading php files.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2021-3277?

It affects 1 product.


Products: Nagios Nagios Xi.

## How do I fix CVE-2021-3277?

No fix has been published for CVE-2021-3277 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-3277 being exploited?

There is no known exploitation of CVE-2021-3277 in the wild and no public exploit code.

## Other vulnerabilities in Nagios Nagios Xi

- [CVE-2021-25296](https://insights.sbomify.com/CVE-2021-25296/): Nagios XI OS Command Injection (high 8.8, exploited in the wild)
- [CVE-2021-25297](https://insights.sbomify.com/CVE-2021-25297/): Nagios XI OS Command Injection (high 8.8, exploited in the wild)
- [CVE-2021-25298](https://insights.sbomify.com/CVE-2021-25298/): Nagios XI OS Command Injection (high 8.8, exploited in the wild)
- [CVE-2019-15949](https://insights.sbomify.com/CVE-2019-15949/): Nagios XI Remote Code Execution (high 8.8, exploited in the wild)
- [CVE-2024-24401](https://insights.sbomify.com/CVE-2024-24401/): SQL injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3277 and fix it if it is affected.

What it is: CVE-2021-3277 is a high-severity vulnerability in Nagios Nagios Xi, published on 7 Jun 2021. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-3277 in the wild and no public exploit code.

Affected product: Nagios Nagios Xi. 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-2021-3277/ (Markdown: https://insights.sbomify.com/CVE-2021-3277/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3277
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3277
- OSV: https://osv.dev/vulnerability/CVE-2021-3277

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3277/
Summaries are generated and may contain mistakes; the official description above is the record.