# CVE-2023-1405: Formidable Forms < 6.2 - Unauthenticated PHP Object Injection

> Unauthenticated attackers can achieve PHP Object Injection via unsafe deserialization in the Formidable Forms plugin, potentially leading to code execution.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Jan 2024
- **Updated:** 11 Jun 2025
- **Also known as:** GHSA-wfgq-9f7c-xcw5

## What is CVE-2023-1405?

CVE-2023-1405 is a high-severity unsafe deserialization vulnerability in Unknown Formidable Forms, published on 16 Jan 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Formidable Forms WordPress plugin before 6.2 unserializes user input, which could allow anonymous users to perform PHP Object Injection when a suitable gadget is present.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2023-1405?

It affects 1 product.


Products: Strategy11 Formidable Forms.

## How do I fix CVE-2023-1405?

No fix has been published for CVE-2023-1405 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-1405 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-1405 exists.

Public exploit code:

- Formidable Forms <= 6.1.2 - Unauthenticated PHP Object Injection (github_poc): https://github.com/RandomRobbieBF/CVE-2023-1405

## Other vulnerabilities in Unknown Formidable Forms

- [CVE-2023-2877](https://insights.sbomify.com/CVE-2023-2877/): Formidable Forms < 6.3.1 - Subscriber+ Remote Code Execution (high 8.8)
- [CVE-2024-11188](https://insights.sbomify.com/CVE-2024-11188/): Cross-site scripting in Formidable Forms – Contact Form Plugin, Survey, Quiz, Payment, Calculator Form & Custom Form Builder (medium 6.1)
- [CVE-2024-0660](https://insights.sbomify.com/CVE-2024-0660/): Formidable Forms <= 6.7.2 - Cross-Site Request Forgery to Stored Cross-Site Scripting (medium 6.1)
- [CVE-2024-23522](https://insights.sbomify.com/CVE-2024-23522/): WordPress Formidable Forms plugin <= 6.7 - Content Injection vulnerability (medium 5.3)
- [CVE-2024-6725](https://insights.sbomify.com/CVE-2024-6725/): Formidable Forms <= 6.11.1 - Authenticated (Subscriber+) Stored Cross-Site Scripting (medium 4.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-1405 and fix it if it is affected.

What it is: CVE-2023-1405 is a high-severity unsafe deserialization vulnerability in Unknown Formidable Forms, published on 16 Jan 2024. 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-2023-1405 exists.

Affected product: Unknown Formidable Forms. 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-2023-1405/ (Markdown: https://insights.sbomify.com/CVE-2023-1405/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-1405
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-1405
- OSV: https://osv.dev/vulnerability/CVE-2023-1405

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-1405/
Summaries are generated and may contain mistakes; the official description above is the record.