Vulnerability identifier: #VU35953

Vulnerability 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

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
LibreNMS
Other software / Other software solutions

Vendor: LibreNMS Project

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

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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/

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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.