Vulnerability identifier: #VU20356

Vulnerability risk: Low

CVSSv3.1: 7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2019-5603

CWE-ID: CWE-264

Exploitation vector: Local

Exploit availability: Yes

Vulnerable software:
FreeBSD
Operating systems & Components / Operating system

Vendor: FreeBSD Foundation

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a reference count overflow within the mqueuefs(5). A local user can obtain access to files, directories, sockets opened by processes owned by other users, including access to files outside of the jail. A local user can run a specially crafted application to gain elevated privileges on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

FreeBSD: 11.0 - 12.0

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External links
http://packetstormsecurity.com/files/153752/FreeBSD-Security-Advisory-FreeBSD-SA-19-15.mqueuefs.html
http://security.FreeBSD.org/advisories/FreeBSD-SA-19:15.mqueuefs.asc
http://security.FreeBSD.org/advisories/FreeBSD-SA-19:24.mqueuefs.asc
http://security.netapp.com/advisory/ntap-20190814-0003/

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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.