---
title: "TYPO3-CORE-SA-2015-006: Brute Force Protection Bypass in backend login"
url: "https://news.typo3.com/security/advisory/typo3-core-sa-2015-006"
description: It has been discovered, that the backend login brute force protection can be bypassed
image: "https://news.typo3.com/_assets/d1e01514e4c4a5b3147940fa2ec50682/Images/og-image-news.jpg"
date: 2026-06-11
modified: 2026-06-11
categories:
  - "Product Updates & Roadmap"
  - TYPO3 CMS
---

# TYPO3-CORE-SA-2015-006: Brute Force Protection Bypass in backend login

- [Product Updates & Roadmap](https://news.typo3.com/article/category/product-updates-roadmap)
- Security / [TYPO3 CMS](https://news.typo3.com/article/category/security/typo3-cms)

TYPO3-CORE-SA-2015-006: Brute Force Protection Bypass in backend login
======================================================================

01 July 2015

![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 backend login brute force protection can be bypassed

- ![](https://news.typo3.com/typo3temp/assets/t3g/blog/gravatar/7569d41262328e5ed8d27b53e03970ec.png)[Helmut Hummel](https://news.typo3.com/article/author/helmut-hummel)

**Component Type:** TYPO3 CMS

**Release Date:** July 1, 2015

**Vulnerable subcomponent:** Backend Login

**Vulnerability Type:** Brute Force Protection Bypass

**Affected Versions:** Versions 6.2.0 to 6.2.13, 7.0.0 to 7.3.0

**Severity:** Low

**Suggested CVSS v2.0:** [AV:N/AC:L/Au:N/C:P/I:N/A:N/E:F/RL:OF/RC:C](http://nvd.nist.gov/cvss.cfm?version=2&vector=(AV:N/AC:L/Au:N/C:P/I:N/A:N/E:F/RL:OF/RC:C))

**CVE:**  not assigned yet

**Problem Description:** The backend login has a basic brute force protection implementation which pauses for 5 seconds if wrong credentials are given. This pause however could be bypassed by forging a special request, making brute force attacks on backend editor credentials more feasible.

**Solution:** Update to TYPO3 versions 6.2.14 or 7.3.1 that fix the problem described.

**Important Note:** These versions move the code to wait for 5 seconds to a place which is not possible to bypass. The consequence is, that frontend logon now also has this protection. Additionally a hook was implemented, making it possible to implement other brute force protection strategies or to remove the 5 second delay, which is the default behavior if no hook is present.

Example Hook registration:

```

$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_userauth.php']['postLoginFailureProcessing'][] = 'My\\Package\\HookClass->hookMethod'
```

**Credits:** Thanks to Franz G. Jahn who discovered and reported the issue.

**General Advice:** Follow the recommendations that are given in the [TYPO3 Security Guide](http://docs.typo3.org/typo3cms/SecurityGuide/ "Opens external link in new window"). Please subscribe to the [typo3-announce](http://lists.typo3.org/cgi-bin/mailman/listinfo/typo3-announce) mailing list.

**General Note:** All security related code changes are tagged so that you can easily look them up on our [review system](https://review.typo3.org/#/q/status:merged+project:Packages/TYPO3.CMS+topic:security,n,z).

![](https://news.typo3.com/typo3temp/assets/t3g/blog/gravatar/bb9efc51bced8582e7b8c235f4b5f2b5.png)

About the Author

[Helmut Hummel](https://news.typo3.com/article/author/helmut-hummel)

[More posts by this author](https://news.typo3.com/article/author/helmut-hummel)