High severity · published Mar 23, 2021
CVE-2021-21357
TYPO3 is an open source PHP based web content management system
8.3
CVSS
1.6%
EPSS
No
On KEV
Description
TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 8.7.40, 9.5.25, 10.4.14, 11.1.1 due to improper input validation, attackers can by-pass restrictions of predefined options and submit arbitrary data in the Form Designer backend module of the Form Framework. In the default configuration of the Form Framework this allows attackers to explicitly allow arbitrary mime-types for file uploads - however, default _fileDenyPattern_ successfully blocked files like _.htaccess_ or _malicious.php_. Besides that, attackers can persist those files in any writable directory of the corresponding TYPO3 installation. A valid backend user account with access to the form module is needed to exploit this vulnerability. This is fixed in versions 8.7.40, 9.5.25, 10.4.14, 11.1.1.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.6% · higher than 76% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TY
Typo3 · Typo3
8.0.0 before 8.7.40; 9.0.0 before 9.5.25; 10.0.0 before 10.4.14; 11.0.0 before 11.1.1 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-21357
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-21357
Third Party Advisory
https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-3vg7-jw9m-pc3f
Release Notes
https://packagist.org/packages/typo3/cms-form
Vendor Advisory
https://typo3.org/security/advisory/typo3-core-sa-2021-003
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TYPO3 is a free and open source Content Management Framework