Remote code execution in vBulletin

1) OS Command Injection

EUVDB-ID: #VU21323

Risk: High

CVSSv3.1: 9.4 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2019-16759

CWE-ID: CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.

The vulnerability exists due to improper input validation in "ajax/render/widget_php" when processing data passed via the "widgetConfig[code]" HTTP POST parameter. A remote unauthenticated attacker can send specially crafted HTTP POST request to the affected application and execute arbitrary OS commands on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Note: The vulnerability is being actively exploited in the wild.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

vBulletin: 5.0 - 5.5.4

External links

http://seclists.org/fulldisclosure/2019/Sep/31
http://www.exploit-db.com/exploits/47447
http://forum.vbulletin.com/forum/vbulletin-announcements/vbulletin-announcements_aa/4422707-vbullet...

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.