PHP code execution in phpBB

1) Phar deserialization

EUVDB-ID: #VU16041

Risk: Low

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-19274

CWE-ID: CWE-502 - Deserialization of Untrusted Data

Exploit availability: No

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.

Mitigation

Update to version 3.2.4.

Vulnerable software versions

phpBB: 3.2.0 - 3.2.3

External links

http://blog.ripstech.com/2018/phpbb3-phar-deserialization-to-remote-code-execution/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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