# CVE-2021-43257: MantisBT CSV Injection unprivileged user access in csv_export.php

> An attacker can inject malicious formulas into CSV exports, leading to code execution or data disclosure when victims open the file in Excel.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 14 Apr 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-rg8f-5p7x-m6wv

## What is CVE-2021-43257?

CVE-2021-43257 is a high-severity code injection vulnerability in Mantisbt Mantisbt, published on 14 Apr 2022. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Lack of Neutralization of Formula Elements in the CSV API of MantisBT before 2.25.3 allows an unprivileged attacker to execute code or gain access to information when a user opens the csv_export.php generated CSV file in Excel.

Weakness: CWE-1236 (Improper Neutralization of Formula Elements in a CSV File)

## Which versions are affected by CVE-2021-43257?

2 open source packages ship an affected version, including mantisbt/mantisbt. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mantisbt/mantisbt` | Packagist | All versions | 2.25.3 |
| `mantisbt/mantisbt` | Packagist | All versions | 2.25.3 |

Products: Mantisbt Mantisbt.

## How do I fix CVE-2021-43257?

Upgrade mantisbt/mantisbt to 2.25.3 or later.

## Is CVE-2021-43257 being exploited?

There is no known exploitation of CVE-2021-43257 in the wild and no public exploit code.

## Other vulnerabilities in Mantisbt Mantisbt

- [CVE-2019-15074](https://insights.sbomify.com/CVE-2019-15074/): MantisBT allows cross-site scripting (XSS) via crafted filename (critical 9.6)
- [CVE-2026-30849](https://insights.sbomify.com/CVE-2026-30849/): MantisBT SOAP API has an authentication bypass vulnerability on MySQL (critical 9.3)
- [CVE-2025-47776](https://insights.sbomify.com/CVE-2025-47776/): MantisBT: Authentication bypass for some passwords due to PHP type juggling (high 8.8)
- [CVE-2017-7615](https://insights.sbomify.com/CVE-2017-7615/): MantisBT allows arbitrary password reset (high 8.8)
- [CVE-2026-33517](https://insights.sbomify.com/CVE-2026-33517/): MantisBT Vulnerable to Stored HTML Injection in Tag Delete Confirmation (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-43257 and fix it if it is affected.

What it is: CVE-2021-43257 is a high-severity code injection vulnerability in Mantisbt Mantisbt, published on 14 Apr 2022. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-43257 in the wild and no public exploit code.

Affected packages and fixed versions:
- mantisbt/mantisbt (Packagist): affected all versions; fixed in 2.25.3
- mantisbt/mantisbt (Packagist): affected all versions; fixed in 2.25.3

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-2021-43257/ (Markdown: https://insights.sbomify.com/CVE-2021-43257/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-43257
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-43257
- OSV: https://osv.dev/vulnerability/CVE-2021-43257

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-43257/
Summaries are generated and may contain mistakes; the official description above is the record.