Vulnerability 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.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Umbraco | Forms | >= 4.0.0, < 4.4.9 |
References
- https://umbraco.com/blog/security-advisory-20th-of-july-2021-patch-is-now-availaPatchVendor Advisory
- https://umbraco.com/blog/security-advisory-security-patches-for-umbraco-forms-reVendor Advisory
- https://umbraco.com/blog/security-advisory-20th-of-july-2021-patch-is-now-availaPatchVendor Advisory
- https://umbraco.com/blog/security-advisory-security-patches-for-umbraco-forms-reVendor Advisory
FAQ
What is CVE-2021-37334?
CVE-2021-37334 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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 occu...
How severe is CVE-2021-37334?
CVE-2021-37334 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2021-37334?
Check the references section above for vendor advisories and patch information. Affected products include: Umbraco Forms.