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

Published: 2022-06-02 | Updated: 2023-04-11

Risk	High
Patch available	YES
Number of vulnerabilities	4
CVE-ID	CVE-2021-4037 CVE-2021-20322 CVE-2022-27666 CVE-2018-13405
CWE-ID	CWE-284 CWE-330 CWE-122 CWE-264
Exploitation vector	Network
Public exploit	Public exploit code for vulnerability #3 is available.
Vulnerable software Subscribe	kernel-rt (Red Hat package) Operating systems & Components / Operating system package or component 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
Vendor	Red Hat Inc.

Security Bulletin

This security bulletin contains information about 4 vulnerabilities.

1) Improper access control

EUVDB-ID: #VU63923

Risk: Low

CVSSv3.1: 3.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-4037

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: No

Description

The vulnerability allows a local user to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to improper access restrictions in the fs/inode.c:inode_init_owner() function logic of the Linux kernel. A local user can create files for the XFS file-system with an unintended group ownership and with group execution and SGID permission bits set to bypass implemented security restrictions and gain unauthorized access to the application.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

kernel-rt (Red Hat package): 4.18.0-305.7.1.rt7.79.el8_4 - 4.18.0-305.45.1.rt7.117.el8_4

Red Hat Enterprise Linux for Real Time: 8.4

Red Hat Enterprise Linux for Real Time for NFV: 8.4

CPE2.3

External links

http://access.redhat.com/errata/RHSA-2022:4835

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 of insufficiently random values

EUVDB-ID: #VU63839

Risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-20322

CWE-ID: CWE-330 - Use of Insufficiently Random Values

Exploit availability: No

Description

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

The vulnerability exists due to an error when processing received ICMP errors. A remote attacker can effectively bypass the source port UDP randomization to gain access to sensitive information.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

kernel-rt (Red Hat package): 4.18.0-305.7.1.rt7.79.el8_4 - 4.18.0-305.45.1.rt7.117.el8_4

Red Hat Enterprise Linux for Real Time: 8.4

Red Hat Enterprise Linux for Real Time for NFV: 8.4

CPE2.3

External links

http://access.redhat.com/errata/RHSA-2022:4835

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.

3) Heap-based buffer overflow

EUVDB-ID: #VU61672

Risk: Low

CVSSv3.1: 6.3 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2022-27666

CWE-ID: CWE-122 - Heap-based Buffer Overflow

Exploit availability: Yes

Description

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

The vulnerability exists due to a boundary error within IPsec ESP transformation code in net/ipv4/esp4.c and net/ipv6/esp6.c in Linux kernel. A local unprivileged user can pass specially crafted data to the system, trigger a heap-based buffer overflow and execute arbitrary code with elevated privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

kernel-rt (Red Hat package): 4.18.0-305.7.1.rt7.79.el8_4 - 4.18.0-305.45.1.rt7.117.el8_4

Red Hat Enterprise Linux for Real Time: 8.4

Red Hat Enterprise Linux for Real Time for NFV: 8.4

CPE2.3

External links

http://access.redhat.com/errata/RHSA-2022:4835

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.

4) Security restrictions bypass

EUVDB-ID: #VU13631

Risk: Low

CVSSv3.1: 4.5 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-13405

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

Exploit availability: No

Description

The vulnerability allows a local attacker to create arbitrary files on the target system.

The vulnerability exists due to the inode_init_owner function, as defined in the fs/inode.c source code file, allows the creation of arbitrary files in set-group identification (SGID) directories. A local attacker can create arbitrary files with unintended group ownership.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

kernel-rt (Red Hat package): 4.18.0-305.7.1.rt7.79.el8_4 - 4.18.0-305.45.1.rt7.117.el8_4

Red Hat Enterprise Linux for Real Time: 8.4

Red Hat Enterprise Linux for Real Time for NFV: 8.4

CPE2.3

External links

http://access.redhat.com/errata/RHSA-2022:4835

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.