Permissions, Privileges, and Access Controls in FreeBSD - CVE-2020-25581
Published: March 2, 2021
Vulnerability identifier: #VU51107
CSH Severity: Low
CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2020-25581
CWE-ID: CWE-264
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
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.
Affected software
FreeBSD
How to mitigate CVE-2020-25581
Install updates from vendor's website.