#VU1344 Symlink attack in Nagios - CVE-2016-9566

Vulnerability identifier: #VU1344

Vulnerability risk: Low

CVSSv4.0: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P/U:Clear]

CVE-ID: CVE-2016-9566

CWE-ID: CWE-61

Exploitation vector: Local

Exploit availability: Yes

Vulnerable software:
Nagios
Server applications / Other server solutions

Vendor: nagios.org

Description

The vulnerability allows a local user obtain elevated privileges on vulnerable system.

The vulnerability exists due to the application handles log files in unsafe manner. A local user with access to Nagios application (nagios account or member of nagios group) can cerate a specially crafted symlink to nagios log file and execute arbitrary command on vulnerable system with root privileges.

Successful exploitation of this vulnerability may allow a local user to obtain full access to vulnerable system.

Mitigation

Vulnerable software versions

Nagios: 4.2.0 - 4.2.3

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External links
https://www.nagios.org/projects/nagios-core/history/4x/
https://legalhackers.com/advisories/Nagios-Exploit-Root-PrivEsc-CVE-2016-9566.html

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

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.