# CVE-2019-19634: class.upload.php in verot.net omits .pht from the set of dangerous file extensions

> An attacker can upload malicious files with .pht extensions to execute arbitrary code due to missing extension validation in the class.upload.php library.

- **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:** 17 Dec 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-2gc7-w4hw-rr2m

## What is CVE-2019-19634?

CVE-2019-19634 is a critical vulnerability in n/a, published on 17 Dec 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

class.upload.php in verot.net class.upload through 1.0.3 and 2.x through 2.0.4, as used in the K2 extension for Joomla! and other products, omits .pht from the set of dangerous file extensions, a similar issue to CVE-2019-19576.

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

## Which versions are affected by CVE-2019-19634?

4 open source packages ship an affected version, including verot/class.upload.php. It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `verot/class.upload.php` | Packagist | All versions to 1.0.3 | None |
| `verot/class.upload.php` | Packagist | All versions to 1.0.3 | None |
| `verot/class.upload.php` | Packagist | From 2.0.0 to 2.0.4 | None |
| `verot/class.upload.php` | Packagist | From 2.0.0 to 2.0.4 | None |

Products: Joomlaworks K2, Verot Project Verot.

## How do I fix CVE-2019-19634?

No fix has been published for CVE-2019-19634 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-19634 being exploited?

There is no known exploitation of CVE-2019-19634 in the wild and no public exploit code.

Public exploit code:

- This is a filter bypass exploit that results in arbitrary file upload and remote code execution in class.upload.php <= 2.0.4 (github_poc): https://github.com/jra89/CVE-2019-19634

## Other vulnerabilities in n/a

- [CVE-2019-19576](https://insights.sbomify.com/CVE-2019-19576/): Remote code execution in verot/class.upload.php (critical 9.8)
- [CVE-2018-7482](https://insights.sbomify.com/CVE-2018-7482/): Path traversal in n/a (high 7.5)
- [CVE-2026-48941](https://insights.sbomify.com/CVE-2026-48941/): Joomla Extension - getk2.org - Unauthenticated folder delete in K2 extension for Joomla < 2.26 (medium 6.5)
- [CVE-2026-48943](https://insights.sbomify.com/CVE-2026-48943/): Joomla Extension - getk2.org - Authenticated user property mass-assignment in K2 extension for Joomla < 2.26 (medium 6.5)
- [CVE-2026-48944](https://insights.sbomify.com/CVE-2026-48944/): Joomla Extension - getk2.org - Exposure of sensitive files via attachment copy in K2 extension for Joomla < 2.26 (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-19634 and fix it if it is affected.

What it is: CVE-2019-19634 is a critical vulnerability in n/a, published on 17 Dec 2019. 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-2019-19634 in the wild and no public exploit code.

Affected packages and fixed versions:
- verot/class.upload.php (Packagist): affected all versions up to 1.0.3; no fix listed
- verot/class.upload.php (Packagist): affected all versions up to 1.0.3; no fix listed
- verot/class.upload.php (Packagist): affected from 2.0.0 up to 2.0.4; no fix listed
- verot/class.upload.php (Packagist): affected from 2.0.0 up to 2.0.4; no fix listed

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-2019-19634/ (Markdown: https://insights.sbomify.com/CVE-2019-19634/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-19634
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-19634
- OSV: https://osv.dev/vulnerability/CVE-2019-19634

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-19634/
Summaries are generated and may contain mistakes; the official description above is the record.