CVE-2021-37334 File upload in n/a
Attackers can upload malicious scripts to execute arbitrary code or delete files by bypassing extension validation in Umbraco Forms.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-37334?
CVE-2021-37334 is a critical vulnerability in n/a, published on 25 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Umbraco Forms version 4.0.0 up to and including 8.7.5 and below are vulnerable to a security flaw that could lead to a remote code execution attack and/or arbitrary file deletion. A vulnerability occurs because validation of the file extension is performed after the file has been stored in a temporary directory. By default, files are stored within the application directory structure at %BASEDIR%/APP_DATA/TEMP/FileUploads/. Whilst access to this directory is restricted by the root web.config file, it is possible to override this restriction by uploading another specially crafted web.config file to the temporary directory. It is possible to exploit this flaw to upload a malicious script file to execute arbitrary code and system commands on the server.
Which versions are affected by CVE-2021-37334?
It affects 1 product.
Products include Umbraco Forms.
How do I fix CVE-2021-37334?
No fix has been published for CVE-2021-37334 yet. Limit exposure of the affected software until one is available.
Is CVE-2021-37334 being exploited?
There is no known exploitation of CVE-2021-37334 in the wild and no public exploit code.
Sources
Also known as GHSA-r3m8-2w46-p3rf.