--- title: "TYPO3-EXT-SA-2017-017: Authentication Bypass in extension \"Frontend User Registration\" (sf_register)" url: "https://news.typo3.com/security/advisory/typo3-ext-sa-2017-017" description: "It has been discovered that the extension \"Frontend User Registration\" (sf_register) is vulnerable to Authentication Bypass." image: "https://news.typo3.com/_assets/d1e01514e4c4a5b3147940fa2ec50682/Images/og-image-news.jpg" date: 2026-06-11 modified: 2026-06-11 categories: - TYPO3 Extensions --- # TYPO3-EXT-SA-2017-017: Authentication Bypass in extension "Frontend User Registration" (sf_register) - Security / [TYPO3 Extensions](https://news.typo3.com/article/category/security/typo3-extensions) TYPO3-EXT-SA-2017-017: Authentication Bypass in extension "Frontend User Registration" (sf\_register) ===================================================================================================== 19 December 2017 ![A laptop screen displaying a list of security advisories](https://news.typo3.com/typo3temp/assets/_processed_/d/c/csm_security_blog_default_77f8e86036.webp) It has been discovered that the extension "Frontend User Registration" (sf\_register) is vulnerable to Authentication Bypass. - ![](https://news.typo3.com/typo3temp/assets/t3g/blog/gravatar/bbf959d8e683550c90ae922aff9145d8.jpeg)[News team](https://news.typo3.com/article/author/news-team) **Release Date:** December 18, 2017 **Component Type:** Third party extension. This extension is not a part of the TYPO3 default installation. **Affected Versions:** version 8.8.0 **Vulnerability Type:** Authentication Bypass **Severity:** Critical **Suggested CVSS v3.0:** [AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N/E:F/RL:O/RC:C](https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N/E:H/RL:O/RC:C "CVSS calculator") ([What's that?](http://buzz.typo3.org/teams/security/article/use-of-common-vulnerability-scoring-system-in-typo3-security-advisories/ "Blog post on CVSS usage")) **CVE:** not assigned yet **Problem Description:** The extension is vulnerable to Authentication Bypass. Frontend users can be authenticated by only knowing their username. **Solution:** An updated version 8.8.1 is available from the TYPO3 Extension Manager and at . Users of the extension are advised to update the extension as soon as possible. **Credits**: Credits go to Manuel Glauser and Sebastian Müller who discovered and reported the vulnerability. **General advice:** Follow the recommendations that are given in the [TYPO3 Security Guide](http://docs.typo3.org/typo3cms/SecurityGuide/ "Initiates file download"). Please subscribe to the [typo3-announce mailing list](http://lists.typo3.org/cgi-bin/mailman/listinfo/typo3-announce "Opens external link in new window") to receive future Security Bulletins via E-mail. ![](https://news.typo3.com/typo3temp/assets/t3g/blog/gravatar/b5c88386e5b1d8fca79d0652427922d2.jpeg) About the Author [News team](https://news.typo3.com/article/author/news-team) [More posts by this author](https://news.typo3.com/article/author/news-team)