# CVE-2021-33898: Deserialization in n/a

> An unsafe unserialize call in Invoice Ninja allows remote code execution if an attacker controls the geoplugin.net response.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:H/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 Jun 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-r5q9-wmfc-68m2

## What is CVE-2021-33898?

CVE-2021-33898 is a high-severity unsafe deserialization vulnerability in n/a, published on 6 Jun 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In Invoice Ninja before 4.4.0, there is an unsafe call to unserialize() in app/Ninja/Repositories/AccountRepository.php that may allow an attacker to deserialize arbitrary PHP classes. In certain contexts, this can result in remote code execution. The attacker's input must be hosted at http://www.geoplugin.net (cleartext HTTP), and thus a successful attack requires spoofing that site or obtaining control of it.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2021-33898?

It affects 1 product.


Products: Invoiceninja Invoice Ninja.

## How do I fix CVE-2021-33898?

No fix has been published for CVE-2021-33898 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-33898 being exploited?

There is no known exploitation of CVE-2021-33898 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2026-29925](https://insights.sbomify.com/CVE-2026-29925/): Server-side request forgery in n/a (high 7.7)
- [CVE-2021-3977](https://insights.sbomify.com/CVE-2021-3977/): Cross-site Scripting (XSS) - Stored in invoiceninja/invoiceninja (medium 6.5)
- [CVE-2026-33628](https://insights.sbomify.com/CVE-2026-33628/): Invoice Ninja Denylist Bypass may Lead to Stored XSS via Invoice Line Items (medium 5.4)
- [CVE-2026-33742](https://insights.sbomify.com/CVE-2026-33742/): Invoice Ninja has Stored XSS via Markdown HTML Injection in Product Notes (medium 5.4)
- [CVE-2017-1000466](https://insights.sbomify.com/CVE-2017-1000466/): Cross-site scripting in n/a (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-33898 and fix it if it is affected.

What it is: CVE-2021-33898 is a high-severity unsafe deserialization vulnerability in n/a, published on 6 Jun 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-2021-33898 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-2021-33898/ (Markdown: https://insights.sbomify.com/CVE-2021-33898/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-33898
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-33898
- OSV: https://osv.dev/vulnerability/CVE-2021-33898

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-33898/
Summaries are generated and may contain mistakes; the official description above is the record.