Vulnerability identifier: #VU51107

Vulnerability risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-25581

CWE-ID: CWE-264

Exploitation vector: Local

Exploit availability: No

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 improper management of internal resources within the jail_remove(2) system call implementation. A process running inside a jail can avoid being killed during jail termination. If a jail is subsequently started with the same root path, a lingering jailed process may be able to exploit the window during which a devfs filesystem is mounted but the jail's devfs ruleset has not been applied, to access device nodes which are ordinarily inaccessible.  If the process is privileged, it may be able to escape the jail and gain full access to the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

FreeBSD: 11.0 - 13.0

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External links
http://www.freebsd.org/security/advisories/FreeBSD-SA-21:04.jail_remove.asc

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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.