Red Hat Enterprise Linux 8.4 Extended Update Support update for kernel-rt

Published: 2022-07-20 | Updated: 2024-06-14

Risk	Medium
Patch available	YES
Number of vulnerabilities	6
CVE-ID	CVE-2020-29368 CVE-2021-4197 CVE-2021-4203 CVE-2022-1012 CVE-2022-1729 CVE-2022-32250
CWE-ID	CWE-787 CWE-264 CWE-416 CWE-401 CWE-362
Exploitation vector	Network
Public exploit	Public exploit code for vulnerability #6 is available.
Vulnerable software Subscribe	Red Hat Enterprise Linux for Real Time - Telecommunications Update Service 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 6 vulnerabilities.

1) Out-of-bounds write

EUVDB-ID: #VU51549

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-2020-29368

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

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

The vulnerability exists due to a boundary error when processing untrusted input within the __split_huge_pmd() function in mm/huge_memory.c in the Linux kernel. A local user can abuse the copy-on-write implementation and gain unintended write access because of a race condition in a THP mapcount check.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for Real Time - Telecommunications Update Service: 8.4

kernel-rt (Red Hat package): 4.18.0-305.7.1.rt7.79.el8_4 - 4.18.0-305.49.1.rt7.121.el8_4

CPE2.3

External links

http://access.redhat.com/errata/RHSA-2022:5633

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) Security restrictions bypass

EUVDB-ID: #VU61258

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-2021-4197

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

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

The vulnerability exists due to missing permissions checks within the cgroups (control groups) functionality of Linux Kernel when writing into a file descriptor. A local low privileged process can trick a higher privileged parent process into writing arbitrary data into files, which can result in denial of service or privileges escalation.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for Real Time - Telecommunications Update Service: 8.4

kernel-rt (Red Hat package): 4.18.0-305.7.1.rt7.79.el8_4 - 4.18.0-305.49.1.rt7.121.el8_4

CPE2.3

External links

http://access.redhat.com/errata/RHSA-2022:5633

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.

3) Use-after-free

EUVDB-ID: #VU63838

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-2021-4203

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 in sock_getsockopt() function in net/core/sock.c due to SO_PEERCRED and SO_PEERGROUPS race with listen() function (and connect() function) in the Linux kernel. A local user can exploit the use-after-free error and crash the system or escalate privileges on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for Real Time - Telecommunications Update Service: 8.4

kernel-rt (Red Hat package): 4.18.0-305.7.1.rt7.79.el8_4 - 4.18.0-305.49.1.rt7.121.el8_4

CPE2.3

External links

http://access.redhat.com/errata/RHSA-2022:5633

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.

4) Memory leak

EUVDB-ID: #VU64079

Risk: Medium

CVSSv3.1: 5.1 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2022-1012

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to insufficient randomization in the net/ipv4/tcp.c when calculating port offsets in Linux kernel cause by small table perturb size. A remote attacker can cause memory leak and gain access to sensitive information.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for Real Time - Telecommunications Update Service: 8.4

kernel-rt (Red Hat package): 4.18.0-305.7.1.rt7.79.el8_4 - 4.18.0-305.49.1.rt7.121.el8_4

CPE2.3

External links

http://access.redhat.com/errata/RHSA-2022:5633

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

5) Race condition

EUVDB-ID: #VU64156

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-2022-1729

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

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

The vulnerability exists due to a race condition within sys_perf_event_open() in Linux kernel. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for Real Time - Telecommunications Update Service: 8.4

kernel-rt (Red Hat package): 4.18.0-305.7.1.rt7.79.el8_4 - 4.18.0-305.49.1.rt7.121.el8_4

CPE2.3

External links

http://access.redhat.com/errata/RHSA-2022:5633

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.

6) Use-after-free

EUVDB-ID: #VU64668

Risk: Low

CVSSv3.1: 7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2022-32250

CWE-ID: CWE-416 - Use After Free

Exploit availability: Yes

Description

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

The vulnerability exists due to a use-after-free incorrect NFT_STATEFUL_EXPR in net/netfilter/nf_tables_api.c in Linux kernel. A local user with ability to create user/net namespaces can execute arbitrary code with root privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for Real Time - Telecommunications Update Service: 8.4

kernel-rt (Red Hat package): 4.18.0-305.7.1.rt7.79.el8_4 - 4.18.0-305.49.1.rt7.121.el8_4

CPE2.3

External links

http://access.redhat.com/errata/RHSA-2022:5633

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. However, proof of concept for this vulnerability is available.