CVE-2021-21357 Broken Access Control in Form Framework
Authenticated backend users can bypass form restrictions to upload arbitrary files, potentially leading to code execution or data modification.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-21357?
CVE-2021-21357 is a high-severity vulnerability in Typo3 Typo3, published on 23 Mar 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 8.7.40, 9.5.25, 10.4.14, 11.1.1 due to improper input validation, attackers can by-pass restrictions of predefined options and submit arbitrary data in the Form Designer backend module of the Form Framework. In the default configuration of the Form Framework this allows attackers to explicitly allow arbitrary mime-types for file uploads - however, default _fileDenyPattern_ successfully blocked files like _.htaccess_ or _malicious.php_. Besides that, attackers can persist those files in any writable directory of the corresponding TYPO3 installation. A valid backend user account with access to the form module is needed to exploit this vulnerability. This is fixed in versions 8.7.40, 9.5.25, 10.4.14, 11.1.1.
Which versions are affected by CVE-2021-21357?
21 open source packages ship an affected version, including typo3/cms-form, typo3 and typo3/cms. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
typo3/cms-form Packagist | From 10.0.0 | 10.4.14 |
typo3/cms-form Packagist | From 10.0.0 | 10.4.14 |
typo3/cms-form Packagist | From 11.0.0 | 11.1.1 |
typo3/cms-form Packagist | From 11.0.0 | 11.1.1 |
typo3/cms-form Packagist | From 8.0.0 | 8.7.40 |
typo3/cms-form Packagist | From 8.0.0 | 8.7.40 |
15 more packages
typo3/cms-form Packagist | From 9.0.0 | 9.5.25 |
typo3/cms-form Packagist | From 9.0.0 | 9.5.25 |
typo3 Bitnami | From 8.0.0 | 8.7.40, 9.5.25, 10.4.14, 11.1.1 |
typo3/cms Packagist | From 10.0.0 | 10.4.14 |
typo3/cms Packagist | From 10.0.0 | 10.4.14 |
typo3/cms Packagist | From 11.0.0 | 11.1.1 |
typo3/cms Packagist | From 11.0.0 | 11.1.1 |
typo3/cms Packagist | From 9.0.0 | 9.5.25 |
typo3/cms Packagist | From 9.0.0 | 9.5.25 |
typo3/cms-core Packagist | From 10.0.0 | 10.4.14 |
typo3/cms-core Packagist | From 10.0.0 | 10.4.14 |
typo3/cms-core Packagist | From 11.0.0 | 11.1.1 |
typo3/cms-core Packagist | From 11.0.0 | 11.1.1 |
typo3/cms-core Packagist | From 9.0.0 | 9.5.25 |
typo3/cms-core Packagist | From 9.0.0 | 9.5.25 |
Products include Typo3 Typo3.
How do I fix CVE-2021-21357?
Upgrade typo3/cms-form to a fixed version for your release line: 10.4.14, 11.1.1, 8.7.40 or 9.5.25.
Is CVE-2021-21357 being exploited?
There is no known exploitation of CVE-2021-21357 in the wild and no public exploit code.
Other vulnerabilities in Typo3 Typo3
- CVE-2009-0258 Indexed Search Engine for TYPO3 Command Execution via Metacharacter Injection
- CVE-2011-3583 Typo3 SQL injection due to faulty prepared statements
- CVE-2011-4628 Typo3 Authentication Bypass
- CVE-2023-24814 Persisted Cross-Site Scripting in Frontend Rendering in typo3
- CVE-2021-41113 Cross-Site-Request-Forgery in Backend URI Handling in Typo3
Sources
Also known as BIT-typo3-2021-21357, GHSA-3vg7-jw9m-pc3f.