# CVE-2020-11066: Improperly Controlled Modification of Dynamically-Determined Object Attributes in TYPO3 CMS

> Attackers can exploit insecure deserialization to delete arbitrary directories or send emails via the web server identity in TYPO3 CMS.

- **Severity:** High 8.7 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/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:** Yes
- **Published:** 13 May 2020
- **Updated:** 4 Aug 2024
- **Also known as:** BIT-typo3-2020-11066, GHSA-2rxh-h6h9-qrqc

## What is CVE-2020-11066?

CVE-2020-11066 is a high-severity unsafe deserialization vulnerability in Typo3 Typo3, published on 13 May 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In TYPO3 CMS greater than or equal to 9.0.0 and less than 9.5.17 and greater than or equal to 10.0.0 and less than 10.4.2, calling unserialize() on malicious user-submitted content can lead to modification of dynamically-determined object attributes and result in triggering deletion of an arbitrary directory in the file system, if it is writable for the web server. It can also trigger message submission via email using the identity of the web site (mail relay). Another insecure deserialization vulnerability is required to actually exploit mentioned aspects. This has been fixed in 9.5.17 and 10.4.2.

Weakness: CWE-1321 (Improperly Controlled Modification of Object Prototype Attributes), CWE-915 (Improperly Controlled Modification of Dynamically-Determined Object Attributes)

## Which versions are affected by CVE-2020-11066?

9 open source packages ship an affected version, including typo3/cms, typo3 and typo3/cms-core. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `typo3/cms` | Packagist | From 10.0.0 | 10.4.2 |
| `typo3/cms` | Packagist | From 10.0.0 | 10.4.2 |
| `typo3/cms` | Packagist | From 9.0.0 | 9.5.17 |
| `typo3/cms` | Packagist | From 9.0.0 | 9.5.17 |
| `typo3` | Bitnami | From 9.0.0 | 9.5.17, 10.4.2 |
| `typo3/cms-core` | Packagist | From 10.0.0 | 10.4.2 |
| `typo3/cms-core` | Packagist | From 10.0.0 | 10.4.2 |
| `typo3/cms-core` | Packagist | From 9.0.0 | 9.5.17 |
| `typo3/cms-core` | Packagist | From 9.0.0 | 9.5.17 |

Products: Typo3 Typo3.

## How do I fix CVE-2020-11066?

Upgrade typo3/cms to a fixed version for your release line: 10.4.2 or 9.5.17.

## Is CVE-2020-11066 being exploited?

There is no known exploitation of CVE-2020-11066 in the wild and no public exploit code.

## Other vulnerabilities in Typo3 Typo3

- [CVE-2009-0258](https://insights.sbomify.com/CVE-2009-0258/): Indexed Search Engine for TYPO3 Command Execution via Metacharacter Injection (critical 10.0)
- [CVE-2011-3583](https://insights.sbomify.com/CVE-2011-3583/): Typo3 SQL injection due to faulty prepared statements (critical 9.8)
- [CVE-2011-4628](https://insights.sbomify.com/CVE-2011-4628/): Typo3 Authentication Bypass (critical 9.8)
- [CVE-2023-24814](https://insights.sbomify.com/CVE-2023-24814/): Persisted Cross-Site Scripting in Frontend Rendering in typo3 (high 8.8)
- [CVE-2021-41113](https://insights.sbomify.com/CVE-2021-41113/): Cross-Site-Request-Forgery in Backend URI Handling in Typo3 (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-11066 and fix it if it is affected.

What it is: CVE-2020-11066 is a high-severity unsafe deserialization vulnerability in Typo3 Typo3, published on 13 May 2020. 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-2020-11066 in the wild and no public exploit code.

Affected packages and fixed versions:
- typo3/cms (Packagist): affected from 10.0.0; fixed in 10.4.2
- typo3/cms (Packagist): affected from 10.0.0; fixed in 10.4.2
- typo3/cms (Packagist): affected from 9.0.0; fixed in 9.5.17
- typo3/cms (Packagist): affected from 9.0.0; fixed in 9.5.17
- typo3 (Bitnami): affected from 9.0.0; fixed in 9.5.17, 10.4.2
- typo3/cms-core (Packagist): affected from 10.0.0; fixed in 10.4.2
- typo3/cms-core (Packagist): affected from 10.0.0; fixed in 10.4.2
- typo3/cms-core (Packagist): affected from 9.0.0; fixed in 9.5.17
- typo3/cms-core (Packagist): affected from 9.0.0; fixed in 9.5.17

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-2020-11066/ (Markdown: https://insights.sbomify.com/CVE-2020-11066/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-11066
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-11066
- OSV: https://osv.dev/vulnerability/CVE-2020-11066

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-11066/
Summaries are generated and may contain mistakes; the official description above is the record.