Ubuntu update for linux

Published: 2022-01-12

Risk	Low
Patch available	YES
Number of vulnerabilities	7
CVE-ID	CVE-2020-26541 CVE-2021-20321 CVE-2021-3760 CVE-2021-4002 CVE-2021-41864 CVE-2021-43056 CVE-2021-43389
CWE-ID	CWE-693 CWE-362 CWE-416 CWE-401 CWE-787 CWE-252 CWE-129
Exploitation vector	Local
Public exploit	N/A
Vulnerable software Subscribe	Ubuntu Operating systems & Components / Operating system linux-image-5.4.0-94-generic-lpae (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-1060-gcp (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-lowlatency (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-generic-lpae (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-oem-osp1 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-gcp-lts-20.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-94-generic (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-oem (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-generic (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-5.4.0-94-lowlatency (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-virtual (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-virtual-hwe-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-snapdragon-hwe-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-lowlatency-hwe-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-generic-lpae-hwe-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-generic-hwe-18.04 (Ubuntu package) Operating systems & Components / Operating system package or component linux-image-gcp (Ubuntu package) Operating systems & Components / Operating system package or component
Vendor	Canonical Ltd.

Security Bulletin

This security bulletin contains information about 7 vulnerabilities.

1) Protection Mechanism Failure

EUVDB-ID: #VU54455

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-2020-26541

CWE-ID: CWE-693 - Protection Mechanism Failure

Exploit availability: No

Description

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

The Linux kernel through 5.8.13 does not properly enforce the Secure Boot Forbidden Signature Database (aka dbx) protection mechanism. This affects certs/blacklist.c and certs/system_keyring.c. A local user can escalate privileges on the system.

Mitigation

Update the affected package linux to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 20.04

linux-image-5.4.0-94-generic-lpae (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-5.4.0-1060-gcp (Ubuntu package): before 5.4.0-1060.64~18.04.1

linux-image-lowlatency (Ubuntu package): before 5.4.0.94.98

linux-image-generic-lpae (Ubuntu package): before 5.4.0.94.98

linux-image-oem-osp1 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp-lts-20.04 (Ubuntu package): before 5.4.0.1060.70

linux-image-5.4.0-94-generic (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-oem (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic (Ubuntu package): before 5.4.0.94.98

linux-image-5.4.0-94-lowlatency (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-virtual (Ubuntu package): before 5.4.0.94.98

linux-image-virtual-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-snapdragon-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-lowlatency-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-lpae-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp (Ubuntu package): before 5.4.0.1060.46

External links

http://ubuntu.com/security/notices/USN-5210-2

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) Race condition

EUVDB-ID: #VU59084

Risk: Low

CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-20321

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 perform a denial of service (DoS) attacks.

The vulnerability exists due to a race condition when accessing file object in the Linux kernel OverlayFS subsystem. A local user can rename files in specific way with OverlayFS and perform a denial of service (DoS) attack.

Mitigation

Update the affected package linux to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 20.04

linux-image-5.4.0-94-generic-lpae (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-5.4.0-1060-gcp (Ubuntu package): before 5.4.0-1060.64~18.04.1

linux-image-lowlatency (Ubuntu package): before 5.4.0.94.98

linux-image-generic-lpae (Ubuntu package): before 5.4.0.94.98

linux-image-oem-osp1 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp-lts-20.04 (Ubuntu package): before 5.4.0.1060.70

linux-image-5.4.0-94-generic (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-oem (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic (Ubuntu package): before 5.4.0.94.98

linux-image-5.4.0-94-lowlatency (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-virtual (Ubuntu package): before 5.4.0.94.98

linux-image-virtual-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-snapdragon-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-lowlatency-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-lpae-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp (Ubuntu package): before 5.4.0.1060.46

External links

http://ubuntu.com/security/notices/USN-5210-2

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: #VU63816

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-2021-3760

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 the NFC stack. A local user can trigger use-after-free error to escalate privileges on the system.

Mitigation

Update the affected package linux to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 20.04

linux-image-5.4.0-94-generic-lpae (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-5.4.0-1060-gcp (Ubuntu package): before 5.4.0-1060.64~18.04.1

linux-image-lowlatency (Ubuntu package): before 5.4.0.94.98

linux-image-generic-lpae (Ubuntu package): before 5.4.0.94.98

linux-image-oem-osp1 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp-lts-20.04 (Ubuntu package): before 5.4.0.1060.70

linux-image-5.4.0-94-generic (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-oem (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic (Ubuntu package): before 5.4.0.94.98

linux-image-5.4.0-94-lowlatency (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-virtual (Ubuntu package): before 5.4.0.94.98

linux-image-virtual-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-snapdragon-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-lowlatency-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-lpae-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp (Ubuntu package): before 5.4.0.1060.46

External links

http://ubuntu.com/security/notices/USN-5210-2

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: #VU63836

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-2021-4002

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

Exploit availability: No

Description

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due memory leak in the Linux kernel's hugetlbfs memory usage. A local user can force the application to leak memory and gain access to sensitive information.

Mitigation

Update the affected package linux to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 20.04

linux-image-5.4.0-94-generic-lpae (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-5.4.0-1060-gcp (Ubuntu package): before 5.4.0-1060.64~18.04.1

linux-image-lowlatency (Ubuntu package): before 5.4.0.94.98

linux-image-generic-lpae (Ubuntu package): before 5.4.0.94.98

linux-image-oem-osp1 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp-lts-20.04 (Ubuntu package): before 5.4.0.1060.70

linux-image-5.4.0-94-generic (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-oem (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic (Ubuntu package): before 5.4.0.94.98

linux-image-5.4.0-94-lowlatency (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-virtual (Ubuntu package): before 5.4.0.94.98

linux-image-virtual-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-snapdragon-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-lowlatency-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-lpae-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp (Ubuntu package): before 5.4.0.1060.46

External links

http://ubuntu.com/security/notices/USN-5210-2

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.

5) Out-of-bounds write

EUVDB-ID: #VU63855

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-2021-41864

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. A local user can gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information.

Mitigation

Update the affected package linux to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 20.04

linux-image-5.4.0-94-generic-lpae (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-5.4.0-1060-gcp (Ubuntu package): before 5.4.0-1060.64~18.04.1

linux-image-lowlatency (Ubuntu package): before 5.4.0.94.98

linux-image-generic-lpae (Ubuntu package): before 5.4.0.94.98

linux-image-oem-osp1 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp-lts-20.04 (Ubuntu package): before 5.4.0.1060.70

linux-image-5.4.0-94-generic (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-oem (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic (Ubuntu package): before 5.4.0.94.98

linux-image-5.4.0-94-lowlatency (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-virtual (Ubuntu package): before 5.4.0.94.98

linux-image-virtual-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-snapdragon-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-lowlatency-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-lpae-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp (Ubuntu package): before 5.4.0.1060.46

External links

http://ubuntu.com/security/notices/USN-5210-2

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) Unchecked Return Value

EUVDB-ID: #VU63921

Risk: Low

CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-43056

CWE-ID: CWE-252 - Unchecked Return Value

Exploit availability: No

Description

The vulnerability allows a local user to perform a denial of service attack.

The vulnerability exists due to an arch/powerpc/kvm/book3s_hv_rmhandlers.S implementation error when handling SRR1 register values. A local user can perform a denial of service attack, when the host is running on Power8.

Mitigation

Update the affected package linux to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 20.04

linux-image-5.4.0-94-generic-lpae (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-5.4.0-1060-gcp (Ubuntu package): before 5.4.0-1060.64~18.04.1

linux-image-lowlatency (Ubuntu package): before 5.4.0.94.98

linux-image-generic-lpae (Ubuntu package): before 5.4.0.94.98

linux-image-oem-osp1 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp-lts-20.04 (Ubuntu package): before 5.4.0.1060.70

linux-image-5.4.0-94-generic (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-oem (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic (Ubuntu package): before 5.4.0.94.98

linux-image-5.4.0-94-lowlatency (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-virtual (Ubuntu package): before 5.4.0.94.98

linux-image-virtual-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-snapdragon-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-lowlatency-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-lpae-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp (Ubuntu package): before 5.4.0.1060.46

External links

http://ubuntu.com/security/notices/USN-5210-2

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.

7) Improper Validation of Array Index

EUVDB-ID: #VU63385

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-2021-43389

CWE-ID: CWE-129 - Improper Validation of Array Index

Exploit availability: No

Description

The vulnerability allows a local user to execute arbitrary code with elevated privileges.

The vulnerability exists due to improper validation of array index in the ISDN CAPI implementation within detach_capi_ctr() function in drivers/isdn/capi/kcapi.c. A local user can send specially crafted data to the system and execute arbitrary code with elevated privileges.

Mitigation

Update the affected package linux to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 20.04

linux-image-5.4.0-94-generic-lpae (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-5.4.0-1060-gcp (Ubuntu package): before 5.4.0-1060.64~18.04.1

linux-image-lowlatency (Ubuntu package): before 5.4.0.94.98

linux-image-generic-lpae (Ubuntu package): before 5.4.0.94.98

linux-image-oem-osp1 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp-lts-20.04 (Ubuntu package): before 5.4.0.1060.70

linux-image-5.4.0-94-generic (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-oem (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic (Ubuntu package): before 5.4.0.94.98

linux-image-5.4.0-94-lowlatency (Ubuntu package): before 5.4.0-94.106~18.04.1

linux-image-virtual (Ubuntu package): before 5.4.0.94.98

linux-image-virtual-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-snapdragon-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-lowlatency-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-lpae-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-generic-hwe-18.04 (Ubuntu package): before 5.4.0.94.106~18.04.83

linux-image-gcp (Ubuntu package): before 5.4.0.1060.46

External links

http://ubuntu.com/security/notices/USN-5210-2

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.