OS Command Injection in LibreNMS

1) OS Command Injection

EUVDB-ID: #VU35953

Risk: High

CVSSv3.1: 8.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2018-20434

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 non-authenticated attacker to execute arbitrary code.

LibreNMS 1.46 allows remote attackers to execute arbitrary OS commands by using the $_POST['community'] parameter to html/pages/addhost.inc.php during creation of a new device, and then making a /ajax_output.php?id=capture&format=text&type=snmpwalk&hostname=localhost request that triggers html/includes/output/capture.inc.php command mishandling.

Mitigation

Install update from vendor's website.

Vulnerable software versions

LibreNMS: 1.46

External links

http://packetstormsecurity.com/files/153188/LibreNMS-addhost-Command-Injection.html
http://packetstormsecurity.com/files/153448/LibreNMS-1.46-addhost-Remote-Code-Execution.html
http://drive.google.com/file/d/1LcGmOY8x-TG-wnNr-cM_f854kxk0etva/view?usp=sharing
http://gist.github.com/mhaskar/516df57aafd8c6e3a1d70765075d372d
http://shells.systems/librenms-v1-46-remote-code-execution-cve-2018-20434/

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?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.