Phar deserialization in phpBB - CVE-2018-19274

 

Phar deserialization in phpBB - CVE-2018-19274

Published: November 23, 2018 / Updated: November 23, 2018


Vulnerability identifier: #VU16041
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2018-19274
CWE-ID: CWE-502
Exploitation vector: Remote access
Exploit availability: No public exploit available
Vendor: phpBB Group
Affected software:
phpBB

Detailed vulnerability description

The vulnerability allows a remote attacker with administrator privileges to execute arbitrary PHP code.

The weakness exists in a feature that utilizes an image editor binary called Imagick due to Phar deserialization if user input is passed unsanitized to any file system function in PHP, such as file_exists(). A remote attacker with access to the Admin Control Panel with founder permissions can upload a malicious image file and edit it with Imagick to execute arbitrary PHP code on the underlying server and then to perform a full site takeover.

How to mitigate CVE-2018-19274

Update to version 3.2.4.

Sources