CVE-2021-21355

Summary

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 the lack of ensuring file extensions belong to configured allowed mime-types, attackers can upload arbitrary data with arbitrary file extensions - however, default fileDenyPattern successfully blocked files like .htaccess or malicious.php. Besides that, UploadedFileReferenceConverter transforming uploaded files into proper FileReference domain model objects handles possible file uploads for other extensions as well - given those extensions use the Extbase MVC framework, make use of FileReference items in their direct or inherited domain model definitions and did not implement their own type converter. In case this scenario applies, UploadedFileReferenceConverter accepts any file mime-type and persists files in the default location. In any way, uploaded files are placed in the default location /fileadmin/user_upload/, in most scenarios keeping the submitted filename - which allows attackers to directly reference files, or even correctly guess filenames used by other individuals, disclosing this information. No authentication is required to exploit this vulnerability. This is fixed in versions 8.7.40, 9.5.25, 10.4.14, 11.1.1.

Affected Software

VendorProductVersion RangeStatus
TYPO3TYPO3.CMS>= 8.0.0, <= 8.7.39affected
TYPO3TYPO3.CMS>= 9.0.0, <= 9.5.24affected
TYPO3TYPO3.CMS>= 10.0.0, <= 10.4.13affected
TYPO3TYPO3.CMS>= 11.0.0, <= 11.1.0affected

Weaknesses

  • CWE-434: CWE-434 Unrestricted Upload of File with Dangerous Type
  • CWE-552: CWE-552 Files or Directories Accessible to External Parties

ADP Enrichment

CVE Program Container

Additional References

References