--- title: "TYPO3-CORE-SA-2020-008: Sensitive Information Disclosure" url: "https://news.typo3.com/security/advisory/typo3-core-sa-2020-008" description: It has been discovered that TYPO3 CMS is susceptible to sensitive information disclosure. image: "https://news.typo3.com/_assets/d1e01514e4c4a5b3147940fa2ec50682/Images/og-image-news.jpg" date: 2026-06-11 modified: 2026-06-11 categories: - "Developer & Technology" - TYPO3 CMS --- # TYPO3-CORE-SA-2020-008: Sensitive Information Disclosure - [Developer & Technology](https://news.typo3.com/article/category/developer-technology) - Security / [TYPO3 CMS](https://news.typo3.com/article/category/security/typo3-cms) TYPO3-CORE-SA-2020-008: Sensitive Information Disclosure ======================================================== 28 July 2020 ![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 TYPO3 CMS is susceptible to sensitive information disclosure. - ![](https://news.typo3.com/typo3temp/assets/t3g/blog/gravatar/b8266fdc667b773926c59081862ab148.jpeg)[Oliver Hader](https://news.typo3.com/article/author/oliver-hader) - **Component Type:** TYPO3 CMS - **Subcomponent:** Backend User Interface (ext:backend) - **Release Date:** July 28, 2020 - **Vulnerability Type:** Sensitive Information Disclosure - **Affected Versions:** 9.0.0-9.5.19, 10.0.0-10.4.5 - **Severity:** High - **Suggested CVSS:** [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C](https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C&version=3.1) - **References:** [CVE-2020-15098](https://nvd.nist.gov/vuln/detail/CVE-2020-15098), [CWE-325](https://cwe.mitre.org/data/definitions/325.html), [CWE-20](https://cwe.mitre.org/data/definitions/20.html), [CWE-200](https://cwe.mitre.org/data/definitions/200.html), [CWE-502](https://cwe.mitre.org/data/definitions/502.html) ### Problem Description It has been discovered that an internal verification mechanism can be used to generate arbitrary checksums. This allows to inject arbitrary data having a valid cryptographic message authentication code (HMAC-SHA1) and can lead to various attack chains as described below. - [TYPO3-CORE-SA-2020-007](https://typo3.org/security/advisory/typo3-core-sa-2020-007), [CVE-2020-15099](https://nvd.nist.gov/vuln/detail/CVE-2020-15099): **Potential Privilege Escalation** - the database server used for a TYPO3 installation must be accessible for an attacker (either via internet or shared hosting network) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C (7.5, high) - [TYPO3-CORE-SA-2016-013](https://typo3.org/security/advisory/typo3-core-sa-2016-013), [CVE-2016-5091](https://nvd.nist.gov/vuln/detail/CVE-2016-5091): **Insecure Deserialization & Remote Code Execution** - an attacker must have access to at least one Extbase plugin or module action in a TYPO3 installation - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C (9.1, critical) The overall severity of this vulnerability is **high (8.2)** based on mentioned attack chains and the requirement of having a valid backend user session (authenticated) to successfully exploit this vulnerability. ### Solution Update to TYPO3 versions 9.5.20 or 10.4.6 that fix the problem described. ### Credits Thanks to TYPO3 security team member Oliver Hader who reported and fixed the issue. ### General Advice Follow the recommendations that are given in the [TYPO3 Security Guide](https://docs.typo3.org/typo3cms/CoreApiReference/Security/Index.html#security). 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 in 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/cc7cba9757f98fbe05023a139119df74.jpeg) About the Author [Oliver Hader](https://news.typo3.com/article/author/oliver-hader) Core Developer at TYPO3 GmbH,Hof, Germany [Website](https://typo3.com)[Twitter](https://twitter.com/ohader)[LinkedIn](https://www.linkedin.com/in/oliverhader/)[Xing](https://www.xing.com/profile/Oliver_Hader) Oliver started to work with TYPO3 in 2005 and was fascinated by the product and its universe. Since 2007 he is member of the TYPO3 Core Team. After going back to university in 2014 for achieving a postgraduate master degree in internet web science, he is now researching on advanced web technology topics in general and for TYPO3 in particular. In his spare time, Oliver loves to go cycling cross-country in the uplands around Hof (Germany) in northern Bavaria - at the region where he's living as well. [More posts by this author](https://news.typo3.com/article/author/oliver-hader)