#VU52842 Arbitrary file upload in Django - CVE-2021-31542

Vulnerability identifier: #VU52842

Vulnerability risk: High

CVSSv4.0: 7.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-31542

CWE-ID: CWE-434

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Django
Web applications / CMS

Vendor: Django Software Foundation

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to insufficient validation of file during file upload via the MultiPartParser, UploadedFile, and FieldFile methods. A remote attacker can upload a file with a specially crafted filename containing directory traversal characters and overwrite arbitrary files on the system.

Successful exploitation of the vulnerability may allow an attacker to compromise the affected system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Django: 2.2 - 2.2.20, 3.0 - 3.2

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External links
https://www.djangoproject.com/weblog/2021/may/04/security-releases/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.