CVE-2023-24814

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.

References

• TYPO3-CORE-SA-2023-001
• TYPO3-CORE-PSA-2023-001 pre-announcement

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

CVE-2023-24814 has a CVSS score of 8.8 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (12.2.0, 11.5.23, 10.4.36, 9.5.40, 8.7.51, 10.4.35); upgrading removes the vulnerable code path.

Kodem intelligence

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=1 is 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.

1. What is CVE-2023-24814? CVE-2023-24814 is a high-severity cross-site scripting (XSS) vulnerability in typo3/cms-core (composer), affecting versions >= 12.0.0, < 12.2.0. It is fixed in 12.2.0, 11.5.23, 10.4.36, 9.5.40, 8.7.51, 10.4.35. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. How severe is CVE-2023-24814? CVE-2023-24814 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by CVE-2023-24814?
   • typo3/cms-core (composer) (versions >= 12.0.0, < 12.2.0)
   • typo3/cms (composer) (versions >= 10.0.0, < 10.4.35)
4. Is there a fix for CVE-2023-24814? Yes. CVE-2023-24814 is fixed in 12.2.0, 11.5.23, 10.4.36, 9.5.40, 8.7.51, 10.4.35. Upgrade to this version or later.
5. Is CVE-2023-24814 exploitable, and should I be worried? Whether CVE-2023-24814 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2023-24814 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2023-24814?
   • Upgrade typo3/cms-core to 12.2.0 or later
   • Upgrade typo3/cms-core to 11.5.23 or later
   • Upgrade typo3/cms-core to 10.4.36 or later
   • Upgrade typo3/cms-core to 9.5.40 or later
   • Upgrade typo3/cms-core to 8.7.51 or later
   • Upgrade typo3/cms to 10.4.35 or later
   • Upgrade typo3/cms to 11.5.23 or later
   • Upgrade typo3/cms to 12.2.0 or later