Red Hat Enterprise Linux 8 update for kernel

1) Buffer overflow

EUVDB-ID: #VU56018

Risk: Low

CVSSv4.0: 7.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2021-22543

CWE-ID: CWE-119 - Memory corruption

Exploit availability: Yes

Description

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

The vulnerability exists due to a boundary error in Linux kernel when handling VM_IO|VM_PFNMAP vmas in KVM. A local user can  can bypass RO checks and cause the pages to get freed while still accessible by the VMM and guest. As a result, an attacker with the ability to start and control a VM to read/write random pages of memory, can trigger memory corruption and execute arbitrary code with elevated privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support: 8.4

Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support: 8.4

Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support: 8.4

Red Hat Enterprise Linux Server - TUS: 8.4

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 8.4

Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 8.4

Red Hat Enterprise Linux Server - AUS: 8.4

Red Hat Enterprise Linux for x86_64 - Extended Update Support: 8.4

Red Hat Enterprise Linux for ARM 64 - Extended Update Support: 8.4

Red Hat CodeReady Linux Builder for ARM 64: 8.0

Red Hat CodeReady Linux Builder for Power, little endian: 8.0

Red Hat CodeReady Linux Builder for x86_64: 8.0

Red Hat Enterprise Linux for ARM 64: 8

Red Hat Enterprise Linux for Power, little endian: 8

Red Hat Enterprise Linux for IBM z Systems: 8

Red Hat Enterprise Linux for x86_64: 8.0

kernel (Red Hat package): before 4.18.0-305.12.1.el8_4

CPE2.3

• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_power_little_endian_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_arm_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_x86_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_tus:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_aus:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_x86_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_arm_64:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_power_little_endian:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_x86_64:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64:8:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian:8:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:8:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux:8.0:*:*:*:*:*:*:*
• cpe:2.3:o:red_hat:kernel_redhat_package:*:*:*:*:*:red_hat_enterprise_linux:*:*

External links

https://access.redhat.com/errata/RHSA-2021:3057

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.

2) Out-of-bounds write

EUVDB-ID: #VU56017

Risk: Low

CVSSv4.0: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Clear]

CVE-ID: CVE-2021-22555

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

Exploit availability: Yes

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 in net/netfilter/x_tables.c in Linux kernel. A local user can run a specially crafted program to trigger an out-of-bounds write and execute arbitrary code with elevated privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support: 8.4

Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support: 8.4

Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support: 8.4

Red Hat Enterprise Linux Server - TUS: 8.4

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 8.4

Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 8.4

Red Hat Enterprise Linux Server - AUS: 8.4

Red Hat Enterprise Linux for x86_64 - Extended Update Support: 8.4

Red Hat Enterprise Linux for ARM 64 - Extended Update Support: 8.4

Red Hat CodeReady Linux Builder for ARM 64: 8.0

Red Hat CodeReady Linux Builder for Power, little endian: 8.0

Red Hat CodeReady Linux Builder for x86_64: 8.0

Red Hat Enterprise Linux for ARM 64: 8

Red Hat Enterprise Linux for Power, little endian: 8

Red Hat Enterprise Linux for IBM z Systems: 8

Red Hat Enterprise Linux for x86_64: 8.0

kernel (Red Hat package): before 4.18.0-305.12.1.el8_4

CPE2.3

• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_power_little_endian_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_arm_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_x86_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_tus:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_aus:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_x86_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_arm_64:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_power_little_endian:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_x86_64:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64:8:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian:8:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:8:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux:8.0:*:*:*:*:*:*:*
• cpe:2.3:o:red_hat:kernel_redhat_package:*:*:*:*:*:red_hat_enterprise_linux:*:*

External links

https://access.redhat.com/errata/RHSA-2021:3057

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?

Yes. This vulnerability is being exploited in the wild.

3) Race condition

EUVDB-ID: #VU54292

Risk: Medium

CVSSv4.0: 7.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2021-3609

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 in the CAN BCM networking protocol (net/can/bcm.c) in the Linux kernel ranging from version 2.6.25 to mainline 5.13-rc6. 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 CodeReady Linux Builder for Power, little endian - Extended Update Support: 8.4

Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support: 8.4

Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support: 8.4

Red Hat Enterprise Linux Server - TUS: 8.4

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 8.4

Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 8.4

Red Hat Enterprise Linux Server - AUS: 8.4

Red Hat Enterprise Linux for x86_64 - Extended Update Support: 8.4

Red Hat Enterprise Linux for ARM 64 - Extended Update Support: 8.4

Red Hat CodeReady Linux Builder for ARM 64: 8.0

Red Hat CodeReady Linux Builder for Power, little endian: 8.0

Red Hat CodeReady Linux Builder for x86_64: 8.0

Red Hat Enterprise Linux for ARM 64: 8

Red Hat Enterprise Linux for Power, little endian: 8

Red Hat Enterprise Linux for IBM z Systems: 8

Red Hat Enterprise Linux for x86_64: 8.0

kernel (Red Hat package): before 4.18.0-305.12.1.el8_4

CPE2.3

• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_power_little_endian_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_arm_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_x86_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_tus:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_aus:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_x86_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64_-_extended_update_support:8.4:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_arm_64:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_power_little_endian:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_x86_64:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64:8:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian:8:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:8:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux:8.0:*:*:*:*:*:*:*
• cpe:2.3:o:red_hat:kernel_redhat_package:*:*:*:*:*:red_hat_enterprise_linux:*:*

External links

https://access.redhat.com/errata/RHSA-2021:3057

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.