Red Hat Enterprise Linux 7.7 update for kpatch-patch

1) Improper locking

EUVDB-ID: #VU51543

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-2020-29661

CWE-ID: CWE-667 - Improper Locking

Exploit availability: No

Description

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

The vulnerability exists due to locking error in the tty subsystem of the Linux kernel in drivers/tty/tty_jobctrl.c. An local user can exploit this vulnerability to trigger a use-after-free error against TIOCSPGRP and execute arbitrary code with elevated privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

kpatch-patch-3_10_0-1062_21_1 (Red Hat package): 1-2.el7

Red Hat Enterprise Linux for x86_64 - Extended Update Support: 7.7

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.7

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.7

Red Hat Enterprise Linux Server - TUS: 7.7

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 7.7

Red Hat Enterprise Linux Server - AUS: 7.7

kpatch-patch-3_10_0-1062_45_1 (Red Hat package): before 1-1.el7

kpatch-patch-3_10_0-1062_43_1 (Red Hat package): before 1-1.el7

kpatch-patch-3_10_0-1062_40_1 (Red Hat package): before 1-1.el7

kpatch-patch-3_10_0-1062_37_1 (Red Hat package): before 1-1.el7

kpatch-patch-3_10_0-1062_36_1 (Red Hat package): before 1-1.el7

kpatch-patch-3_10_0-1062_33_1 (Red Hat package): before 1-1.el7

kpatch-patch-3_10_0-1062_31_3 (Red Hat package): before 1-1.el7

kpatch-patch-3_10_0-1062_31_2 (Red Hat package): before 1-1.el7

kpatch-patch-3_10_0-1062_30_1 (Red Hat package): before 1-1.el7

kpatch-patch-3_10_0-1062_26_1 (Red Hat package): before 1-1.el7

External links

http://access.redhat.com/errata/RHSA-2021:1031

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.