CVE-2021-21355

Published Mar 23, 2021

Last updated 4 years ago

Overview

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 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.
Source
security-advisories@github.com
NVD status
Analyzed

Social media

Hype score
Not currently trending

Risk scores

CVSS 3.1

Type
Primary
Base score
8.6
Impact score
4.7
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
Severity
HIGH

CVSS 2.0

Type
Primary
Base score
7.5
Impact score
6.4
Exploitability score
10
Vector string
AV:N/AC:L/Au:N/C:P/I:P/A:P

Weaknesses

security-advisories@github.com
CWE-434

Configurations