SUSE update for the Linux Kernel (Live Patch 13 for SLE 12 SP4)

Published: 2021-03-17

Risk	Medium
Patch available	YES
Number of vulnerabilities	4
CVE-ID	CVE-2020-27786 CVE-2020-28374 CVE-2020-29368 CVE-2021-3347
CWE-ID	CWE-416 CWE-22 CWE-787
Exploitation vector	Network
Public exploit	Public exploit code for vulnerability #1 is available.
Vulnerable software	SUSE Linux Enterprise Live Patching Operating systems & Components / Operating system kgraft-patch-4_12_14-95_48-default Operating systems & Components / Operating system package or component kgraft-patch-4_12_14-95_51-default Operating systems & Components / Operating system package or component
Vendor	SUSE

Security Bulletin

This security bulletin contains information about 4 vulnerabilities.

1) Use-after-free

EUVDB-ID: #VU83583

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-2020-27786

CWE-ID: CWE-416 - Use After Free

Exploit availability: Yes

Description

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

The vulnerability exists due to a use-after-free error within the MIDI implementation in Linux kernel. A local authenticated user can trigger a use-after-free error and escalate privileges on the system.

Mitigation

Update the affected package the Linux Kernel (Live Patch 13 for SLE 12 SP4) to the latest version.

Vulnerable software versions

SUSE Linux Enterprise Live Patching: 12-SP4

kgraft-patch-4_12_14-95_48-default: before 10-2.2

kgraft-patch-4_12_14-95_51-default: before 9-2.2

CPE2.3

External links

https://www.suse.com/support/update/announcement/2021/suse-su-20210826-1/

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) Path traversal

EUVDB-ID: #VU49914

Risk: Medium

CVSSv4.0: 6.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-28374

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Exploit availability: No

Description

The vulnerability allows a remote user to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences in drivers/target/target_core_xcopy.c in the Linux kernel. A remote user with access to iSCSI LUN can send a specially crafted XCOPY request and read or write arbitrary files on the system.

Mitigation

Update the affected package the Linux Kernel (Live Patch 13 for SLE 12 SP4) to the latest version.

Vulnerable software versions

SUSE Linux Enterprise Live Patching: 12-SP4

kgraft-patch-4_12_14-95_48-default: before 10-2.2

kgraft-patch-4_12_14-95_51-default: before 9-2.2

CPE2.3

External links

https://www.suse.com/support/update/announcement/2021/suse-su-20210826-1/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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

3) Out-of-bounds write

EUVDB-ID: #VU51549

Risk: Low

CVSSv4.0: 5.9 [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:U/U:Clear]

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

Update the affected package the Linux Kernel (Live Patch 13 for SLE 12 SP4) to the latest version.

Vulnerable software versions

SUSE Linux Enterprise Live Patching: 12-SP4

kgraft-patch-4_12_14-95_48-default: before 10-2.2

kgraft-patch-4_12_14-95_51-default: before 9-2.2

CPE2.3

External links

https://www.suse.com/support/update/announcement/2021/suse-su-20210826-1/

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) Use-after-free

EUVDB-ID: #VU52035

Risk: Low

CVSSv4.0: 5.9 [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:U/U:Clear]

CVE-ID: CVE-2021-3347

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

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

The vulnerability exists due to a use-after-free error when handling PI futexes. A local user can run a specially crafted program to trigger a use-after-free error and execute arbitrary code with elevated privileges.

Mitigation

Update the affected package the Linux Kernel (Live Patch 13 for SLE 12 SP4) to the latest version.

Vulnerable software versions

SUSE Linux Enterprise Live Patching: 12-SP4

kgraft-patch-4_12_14-95_48-default: before 10-2.2

kgraft-patch-4_12_14-95_51-default: before 9-2.2

CPE2.3

External links

https://www.suse.com/support/update/announcement/2021/suse-su-20210826-1/

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.