Gentoo update for FreeRADIUS

1) UNIX Hard Link

EUVDB-ID: #VU50016

Risk: Low

CVSSv4.0: 4.4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: N/A

CWE-ID: CWE-62 - UNIX Hard Link

Exploit availability: No

Description

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

The vulnerability exists in the way FreeRadius is being started on the system. The systemd service file for freeradius runs "chown -R" on a directory before it starts:

  ExecStartPre=-/bin/chown -R radius.radius /run/radiusd

That can be exploited by the "radius" user to gain root privileges. After the service has been started once, the radius user can place a hard link to a root-owned file in /run/radiusd. If the service is later restarted, then the "chown -R" command will give away ownership of that root-owned file to the "radius" user.

As a result, a local user can execute arbitrary code on the system as root.

Mitigation

Update the affected packages.
net-dialup/freeradius to version: 3.0.20-r1

Vulnerable software versions

Gentoo Linux: All versions

CPE2.3

• cpe:2.3:o:gentoo:gentoo_linux:*:*:*:*:*:*:*:*

External links

https://security.gentoo.org/
https://security.gentoo.org/glsa/202101-27

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.