SB2018010205 - Arbitrary file upload in Craft CMS



SB2018010205 - Arbitrary file upload in Craft CMS

Published: January 2, 2018

Security Bulletin ID SB2018010205
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Arbitrary file upload (CVE-ID: CVE-2018-3814)

CWE-ID: CWE-434 - Unrestricted Upload of File with Dangerous Type

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to execute arbitrary PHP code on the target system.

The vulnerability exists due to insufficient validation of user-supplied data when uploading files via "Assets->Upload files" screen. A remote authenticated attacker can upload .jpg file with PHP code inside, then use the "Replace it" option to rename the file and add .php extension to it. As a result the uploaded PHP code will be executed on the server.



Remediation

Install update from vendor's website.