Impact Analysis

If exploited by an administrator-level backend user, this vulnerability can cause a denial-of-service condition in the TYPO3 backend user interface, effectively blocking access and disrupting administrative operations. [1]

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Executive Summary

This vulnerability is a medium-severity Denial of Service (DoS) issue in the TYPO3 CMS Bookmark Toolbar component. It occurs because of insufficient input validation, allowing an administrator-level backend user to save manipulated data in the bookmark toolbar. This triggers an uncaught exception that causes a general error state, blocking further access to the backend user interface. [1]

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Detection Guidance

This vulnerability can be detected by verifying the TYPO3 CMS version in use to see if it falls within the affected ranges: 11.0.0–11.5.47, 12.0.0–12.4.36, or 13.0.0–13.4.17. Since the issue involves manipulated data in the bookmark toolbar causing a denial-of-service condition triggered by administrator-level backend users, monitoring for unusual backend UI errors or denial-of-service symptoms after bookmark toolbar changes may help detect exploitation attempts. Specific detection commands are not provided in the available resources. [1]

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Mitigation Strategies

The immediate mitigation step is to update TYPO3 CMS to a fixed version: 11.5.48 ELTS, 12.4.37 LTS, or 13.4.18 LTS. This update resolves the issue by fixing the insufficient input validation in the bookmark toolbar component. Additionally, restricting administrator-level backend user access and monitoring for suspicious activity related to bookmark toolbar modifications can help reduce risk until the update is applied. [1]

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