CVE-2023-24814 is a high-severity (CVSS 8.8) Cross-site Scripting (XSS) vulnerability in typo3/cms-core. 2 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for typo3/cms-core — see the affected versions and patch details below.
Persisted Cross-Site Scripting in Frontend Rendering in typo3
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-24814.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
typo3/cms-core🐘typo3/cms-core🐘typo3/cms-core🐘typo3/cms-core🐘typo3/cms-core🐘typo3/cms🐘typo3/cms🐘typo3/cmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
CVSS:
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L/E:F/RL:O/RC:C(8.2)
Problem
TYPO3 core component GeneralUtility::getIndpEnv() uses the unfiltered server environment variable PATH_INFO, which allows attackers to inject malicious content.
In combination with the TypoScript setting config.absRefPrefix=auto, attackers can inject malicious HTML code into pages that have not yet been rendered and cached. As a result, injected values would be cached and delivered to other website visitors (persisted cross-site scripting).
Individual code which relies on the resolved value of GeneralUtility::getIndpEnv('SCRIPT_NAME') and corresponding usages (as shown below) are vulnerable as well.
GeneralUtility::getIndpEnv('PATH_INFO')GeneralUtility::getIndpEnv('SCRIPT_NAME')GeneralUtility::getIndpEnv('TYPO3_REQUEST_DIR')GeneralUtility::getIndpEnv('TYPO3_REQUEST_SCRIPT')GeneralUtility::getIndpEnv('TYPO3_SITE_PATH')GeneralUtility::getIndpEnv('TYPO3_SITE_SCRIPT')GeneralUtility::getIndpEnv('TYPO3_SITE_URL')
Installations of TYPO3 versions 8.7 and 9.x are probably only affected when server environment variable TYPO3_PATH_ROOT is defined - which is the case if they were installed via Composer.
Additional investigations confirmed that Apache and Microsoft IIS web servers using PHP-CGI (FPM, FCGI/FastCGI, or similar) are affected. There might be the risk that nginx is vulnerable as well. It was not possible to exploit Apache/mod_php scenarios.
Solution
The usage of server environment variable PATH_INFO has been removed from corresponding processings in GeneralUtility::getIndpEnv(). Besides that, the public property TypoScriptFrontendController::$absRefPrefix is encoded for both being used as a URI component and for being used as a prefix in an HTML context. This mitigates the cross-site scripting vulnerability.
Update to TYPO3 versions 8.7.51 ELTS, 9.5.40 ELTS, 10.4.36 LTS, 11.5.23 LTS and 12.2.0 that fix the problem described above.
ℹ️ Strong security defaults - Manual actions required Any web server using PHP-CGI (FPM, FCGI/FastCGI, or similar) needs to ensure that the PHP setting
cgi.fix_pathinfo=1is used, which is the default PHP setting. In case this setting is not enabled, an exception is thrown to avoid continuing with invalid path information.
For websites that cannot be patched timely the TypoScript setting config.absRefPrefix at least should be set to a static path value, instead of using auto - e.g. config.absRefPrefix=/ - this does not fix all aspects of the vulnerability, and is just considered to be an intermediate mitigation to the most prominent manifestation.
References
- TYPO3-CORE-SA-2023-001
- TYPO3-CORE-PSA-2023-001 pre-announcement
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | typo3/cms-core | ≥ 12.0.0&&< 12.2.0 | 12.2.0composer require typo3/cms-core:^12.2.0 |
| 🐘Packagist | typo3/cms-core | ≥ 11.0.0&&< 11.5.23 | 11.5.23composer require typo3/cms-core:^11.5.23 |
| 🐘Packagist | typo3/cms-core | ≥ 10.0.0&&< 10.4.36 | 10.4.36composer require typo3/cms-core:^10.4.36 |
| 🐘Packagist | typo3/cms-core | ≥ 9.0.0&&< 9.5.40 | 9.5.40composer require typo3/cms-core:^9.5.40 |
| 🐘Packagist | typo3/cms-core | ≥ 8.7.0&&< 8.7.51 | 8.7.51composer require typo3/cms-core:^8.7.51 |
| 🐘Packagist | typo3/cms | ≥ 10.0.0&&< 10.4.35 | 10.4.35composer require typo3/cms:^10.4.35 |
Affected Products
typo3typo3Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3/cms-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update typo3/cms-core to 12.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-24814 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2023-24814 in your dependencies?
Find it across Packagist, including transitive dependencies.