SUSE update for the Linux Kernel (Live Patch 40 for SLE 12 SP3)

Published: 2021-09-23

Risk	Low
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2021-3653 CVE-2021-38198
CWE-ID	CWE-264 CWE-732
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	SUSE Linux Enterprise Server for SAP Operating systems & Components / Operating system SUSE Linux Enterprise Server Operating systems & Components / Operating system kgraft-patch-4_4_180-94_147-default-debuginfo Operating systems & Components / Operating system package or component kgraft-patch-4_4_180-94_147-default Operating systems & Components / Operating system package or component kgraft-patch-4_4_180-94_144-default-debuginfo Operating systems & Components / Operating system package or component kgraft-patch-4_4_180-94_144-default Operating systems & Components / Operating system package or component kgraft-patch-4_4_180-94_141-default-debuginfo Operating systems & Components / Operating system package or component kgraft-patch-4_4_180-94_141-default Operating systems & Components / Operating system package or component kgraft-patch-4_4_180-94_138-default-debuginfo Operating systems & Components / Operating system package or component kgraft-patch-4_4_180-94_138-default Operating systems & Components / Operating system package or component kgraft-patch-4_4_180-94_135-default-debuginfo Operating systems & Components / Operating system package or component kgraft-patch-4_4_180-94_135-default Operating systems & Components / Operating system package or component kgraft-patch-4_4_180-94_130-default-debuginfo Operating systems & Components / Operating system package or component kgraft-patch-4_4_180-94_130-default Operating systems & Components / Operating system package or component
Vendor	SUSE

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Security restrictions bypass

EUVDB-ID: #VU56904

Risk: Low

CVSSv4.0: 5.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-3653

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

Exploit availability: No

Description

The vulnerability allows a malicious guest to escalate privileges on the system.

The vulnerability exists due to improperly imposed security restrictions within the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "int_ctl" field, this issue could allow a malicious L1 to enable AVIC support (Advanced Virtual Interrupt Controller) for the L2 guest.

As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape.

Mitigation

Update the affected package the Linux Kernel (Live Patch 40 for SLE 12 SP3) to the latest version.

Vulnerable software versions

SUSE Linux Enterprise Server for SAP: 12-SP3

SUSE Linux Enterprise Server: 12-SP3-LTSS

kgraft-patch-4_4_180-94_147-default-debuginfo: before 3-2.2

kgraft-patch-4_4_180-94_147-default: before 3-2.2

kgraft-patch-4_4_180-94_144-default-debuginfo: before 6-2.2

kgraft-patch-4_4_180-94_144-default: before 6-2.2

kgraft-patch-4_4_180-94_141-default-debuginfo: before 9-2.2

kgraft-patch-4_4_180-94_141-default: before 9-2.2

kgraft-patch-4_4_180-94_138-default-debuginfo: before 10-2.2

kgraft-patch-4_4_180-94_138-default: before 10-2.2

kgraft-patch-4_4_180-94_135-default-debuginfo: before 12-2.3

kgraft-patch-4_4_180-94_135-default: before 12-2.3

kgraft-patch-4_4_180-94_130-default-debuginfo: before 14-2.3

kgraft-patch-4_4_180-94_130-default: before 14-2.3

CPE2.3

External links

https://www.suse.com/support/update/announcement/2021/suse-su-20213196-1/

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.

2) Incorrect permission assignment for critical resource

EUVDB-ID: #VU63665