CVE-2021-21365 Cross-Site Scripting in Content Rendering
A valid backend user can inject malicious scripts into frontend content rendering in the TYPO3 Bootstrap Package, potentially leading to code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-21365?
CVE-2021-21365 is a medium-severity cross-site scripting vulnerability in Typo3 Typo3, published on 27 Apr 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Bootstrap Package is a theme for TYPO3. It has been discovered that rendering content in the website frontend is vulnerable to cross-site scripting. A valid backend user account is needed to exploit this vulnerability. Users of the extension, who have overwritten the affected templates with custom code must manually apply the security fix. Update to version 7.1.2, 8.0.8, 9.1.4, 10.0.10 or 11.0.3 of the Bootstrap Package that fix the problem described. Updated version are available from the TYPO3 extension manager, Packagist and at https://extensions.typo3.org/extension/download/bootstrap_package/.
Weakness: CWE-79
Which versions are affected by CVE-2021-21365?
13 open source packages ship an affected version, including typo3 and bk2k/bootstrap-package. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
typo3 Bitnami | All versions | 7.1.2, 8.0.8, 9.0.4, 9.1.3, 10.0.10, 11.0.3 |
bk2k/bootstrap-package Packagist | From 10.0.0 | 10.0.10 |
bk2k/bootstrap-package Packagist | From 10.0.0 | 10.0.10 |
bk2k/bootstrap-package Packagist | From 11.0.0 | 11.0.3 |
bk2k/bootstrap-package Packagist | From 11.0.0 | 11.0.3 |
bk2k/bootstrap-package Packagist | From 7.1.0 | 7.1.2 |
7 more packages
bk2k/bootstrap-package Packagist | From 7.1.0 | 7.1.2 |
bk2k/bootstrap-package Packagist | From 8.0.0 | 8.0.8 |
bk2k/bootstrap-package Packagist | From 8.0.0 | 8.0.8 |
bk2k/bootstrap-package Packagist | From 9.0.0 | 9.0.4 |
bk2k/bootstrap-package Packagist | From 9.0.0 | 9.0.4 |
bk2k/bootstrap-package Packagist | From 9.1.0 | 9.1.3 |
bk2k/bootstrap-package Packagist | From 9.1.0 | 9.1.3 |
Products include Typo3 Typo3.
How do I fix CVE-2021-21365?
Upgrade typo3 to a fixed version for your release line: 7.1.2, 8.0.8, 9.0.4 or 9.1.3.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2021-21365 being exploited?
There is no known exploitation of CVE-2021-21365 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-typo3-2021-21365, GHSA-p48w-vf3c-rqjx.