# CVE-2020-35951: Missing authorization in n/a

> Unauthenticated attackers can delete arbitrary files, including configuration files, causing site downtime and potential reinstallation under attacker control.

- **Severity:** Critical 9.9 (`CVSS:3.1/AC:L/AV:N/A:H/C:L/I:L/PR:N/S:C/UI:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Jan 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-r275-5g72-r3ph

## What is CVE-2020-35951?

CVE-2020-35951 is a critical missing authorization vulnerability in n/a, published on 1 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in the Quiz and Survey Master plugin before 7.0.1 for WordPress. It allows users to delete arbitrary files such as wp-config.php file, which could effectively take a site offline and allow an attacker to reinstall with a WordPress instance under their control. This occurred via qsm_remove_file_fd_question, which allowed unauthenticated deletions (even though it was only intended for a person to delete their own quiz-answer files).

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2020-35951?

It affects 1 product.


Products: Expresstech Quiz and Survey Master.

## How do I fix CVE-2020-35951?

No fix has been published for CVE-2020-35951 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-35951 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-35951 exists.

Public exploit code:

- Wordpress Quiz and Survey Master <7.0.1 - Arbitrary File Deletion (nuclei): http/cves/2020/CVE-2020-35951.yaml

## Other vulnerabilities in n/a

- [CVE-2020-35949](https://insights.sbomify.com/CVE-2020-35949/): File upload in n/a (critical 10.0)
- [CVE-2024-3592](https://insights.sbomify.com/CVE-2024-3592/): SQL injection in Quiz and Survey Master (QSM) – Easy Quiz and Survey Maker (critical 9.9)
- [CVE-2024-5606](https://insights.sbomify.com/CVE-2024-5606/): Quiz And Survey Master < 9.0.2 - Contributor+ SQLi (high 8.8)
- [CVE-2022-0180](https://insights.sbomify.com/CVE-2022-0180/): Cross-site request forgery in Quiz And Survey Master (high 8.8)
- [CVE-2021-24221](https://insights.sbomify.com/CVE-2021-24221/): Quiz And Survey Master < 7.1.12 - Authenticated SQL injection via shortcode (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-35951 and fix it if it is affected.

What it is: CVE-2020-35951 is a critical missing authorization vulnerability in n/a, published on 1 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-35951 exists.

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-2020-35951/ (Markdown: https://insights.sbomify.com/CVE-2020-35951/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-35951
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-35951
- OSV: https://osv.dev/vulnerability/CVE-2020-35951

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-35951/
Summaries are generated and may contain mistakes; the official description above is the record.