Red Hat Enterprise Linux 7 update for kernel-rt

Published: 2022-04-06

Risk	Low
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2021-4083 CVE-2021-4028
CWE-ID	CWE-416
Exploitation vector	Local
Public exploit	N/A
Vulnerable software Subscribe	Red Hat Enterprise Linux for Real Time Operating systems & Components / Operating system Red Hat Enterprise Linux for Real Time for NFV Operating systems & Components / Operating system kernel-rt (Red Hat package) Operating systems & Components / Operating system package or component
Vendor	Red Hat Inc.

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Use-after-free

EUVDB-ID: #VU61246

Risk: Low

CVSSv3.1: 6.1 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-4083

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

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

The vulnerability exists due to a use-after-free error within the Linux kernel's garbage collection for Unix domain socket file handlers. A local user can call close() and fget() simultaneously and can potentially trigger a race condition, which in turn leads to a use-after-free error and allows privilege escalation.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for Real Time: 7

Red Hat Enterprise Linux for Real Time for NFV: 7

kernel-rt (Red Hat package): before 3.10.0-1160.62.1.rt56.1203.el7

External links

http://access.redhat.com/errata/RHSA-2022:1199

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.

2) Use-after-free

EUVDB-ID: #VU60797