CVE-2021-28689

Upstream information

CVE-2021-28689 at MITRE

Description

x86: Speculative vulnerabilities with bare (non-shim) 32-bit PV guests 32-bit x86 PV guest kernels run in ring 1. At the time when Xen was developed, this area of the i386 architecture was rarely used, which is why Xen was able to use it to implement paravirtualisation, Xen's novel approach to virtualization. In AMD64, Xen had to use a different implementation approach, so Xen does not use ring 1 to support 64-bit guests. With the focus now being on 64-bit systems, and the availability of explicit hardware support for virtualization, fixing speculation issues in ring 1 is not a priority for processor companies. Indirect Branch Restricted Speculation (IBRS) is an architectural x86 extension put together to combat speculative execution sidechannel attacks, including Spectre v2. It was retrofitted in microcode to existing CPUs. For more details on Spectre v2, see: http://xenbits.xen.org/xsa/advisory-254.html However, IBRS does not architecturally protect ring 0 from predictions learnt in ring 1. For more details, see: https://software.intel.com/security-software-guidance/deep-dives/deep-dive-indirect-branch-restricted-speculation Similar situations may exist with other mitigations for other kinds of speculative execution attacks. The situation is quite likely to be similar for speculative execution attacks which have yet to be discovered, disclosed, or mitigated.

---

SUSE information

Overall state of this security issue: Pending

This issue is currently rated as having moderate severity.

CVSS v2 Scores

	National Vulnerability Database
Base Score	2.1
Vector	AV:L/AC:L/Au:N/C:P/I:N/A:N
Access Vector	Local
Access Complexity	Low
Authentication	None
Confidentiality Impact	Partial
Integrity Impact	None
Availability Impact	None

CVSS v3 Scores

	National Vulnerability Database	SUSE
Base Score	5.5	5.9
Vector	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N	CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
Access Vector	Local	Local
Access Complexity	Low	High
Privileges Required	Low	None
User Interaction	None	None
Scope	Unchanged	Changed
Confidentiality Impact	High	High
Integrity Impact	None	None
Availability Impact	None	None
CVSSv3 Version	3.1	3.1

SUSE Bugzilla entry: 1185104 [NEW]

SUSE Security Advisories:

• SUSE-SU-2021:1648-1, published Wed May 19 16:29:31 UTC 2021

List of released packages

Product(s)	Fixed package version(s)	References
Image SLES12-SP4-EC2-HVM-BYOS Image SLES12-SP4-SAP-EC2-HVM Image SLES12-SP4-SAP-EC2-HVM-BYOS	xen-libs >= 4.11.4_18-2.54.1 xen-tools-domU >= 4.11.4_18-2.54.1
SUSE Linux Enterprise Server 12 SP4-ESPOS	xen >= 4.11.4_18-2.54.1 xen-doc-html >= 4.11.4_18-2.54.1 xen-libs >= 4.11.4_18-2.54.1 xen-libs-32bit >= 4.11.4_18-2.54.1 xen-tools >= 4.11.4_18-2.54.1 xen-tools-domU >= 4.11.4_18-2.54.1	Patchnames: SUSE-SLE-SERVER-12-SP4-ESPOS-2021-1648
SUSE Linux Enterprise Server 12 SP4-LTSS	xen >= 4.11.4_18-2.54.1 xen-doc-html >= 4.11.4_18-2.54.1 xen-libs >= 4.11.4_18-2.54.1 xen-libs-32bit >= 4.11.4_18-2.54.1 xen-tools >= 4.11.4_18-2.54.1 xen-tools-domU >= 4.11.4_18-2.54.1	Patchnames: SUSE-SLE-SERVER-12-SP4-LTSS-2021-1648
SUSE Linux Enterprise Server for SAP Applications 12 SP4	xen >= 4.11.4_18-2.54.1 xen-doc-html >= 4.11.4_18-2.54.1 xen-libs >= 4.11.4_18-2.54.1 xen-libs-32bit >= 4.11.4_18-2.54.1 xen-tools >= 4.11.4_18-2.54.1 xen-tools-domU >= 4.11.4_18-2.54.1	Patchnames: SUSE-SLE-SAP-12-SP4-2021-1648
SUSE OpenStack Cloud 9	xen >= 4.11.4_18-2.54.1 xen-doc-html >= 4.11.4_18-2.54.1 xen-libs >= 4.11.4_18-2.54.1 xen-libs-32bit >= 4.11.4_18-2.54.1 xen-tools >= 4.11.4_18-2.54.1 xen-tools-domU >= 4.11.4_18-2.54.1	Patchnames: SUSE-OpenStack-Cloud-9-2021-1648
SUSE OpenStack Cloud Crowbar 9	xen >= 4.11.4_18-2.54.1 xen-doc-html >= 4.11.4_18-2.54.1 xen-libs >= 4.11.4_18-2.54.1 xen-libs-32bit >= 4.11.4_18-2.54.1 xen-tools >= 4.11.4_18-2.54.1 xen-tools-domU >= 4.11.4_18-2.54.1	Patchnames: SUSE-OpenStack-Cloud-Crowbar-9-2021-1648

---

First public cloud image revisions this CVE is fixed in:

• amazon/suse-sles-12-sp4-byos-v20220128-hvm-ssd-x86_64
• amazon/suse-sles-sap-12-sp4-byos-v20220201-hvm-ssd-x86_64
• amazon/suse-sles-sap-12-sp4-v20220304-hvm-ssd-x86_64

---

Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification.

Product(s)	Source package	State
HPE Helion OpenStack 8	xen	Affected
SUSE CaaS Platform 4.0	xen	Affected
SUSE CaaS Platform 4.5	xen	Affected
SUSE Enterprise Storage 6	xen	Affected
SUSE Enterprise Storage 7	xen	Affected
SUSE Linux Enterprise Desktop 15 SP2	xen	Affected
SUSE Linux Enterprise Desktop 15 SP3	xen	Affected
SUSE Linux Enterprise Desktop 15 SP4	xen	Not affected
SUSE Linux Enterprise High Performance Computing 12 SP5	xen	Affected
SUSE Linux Enterprise High Performance Computing 15 LTSS	xen	Affected
SUSE Linux Enterprise High Performance Computing 15 SP1 ESPOS	xen	Affected
SUSE Linux Enterprise High Performance Computing 15 SP1 LTSS	xen	Affected
SUSE Linux Enterprise High Performance Computing 15 SP2	xen	Affected
SUSE Linux Enterprise High Performance Computing 15 SP2 ESPOS	xen	Affected
SUSE Linux Enterprise High Performance Computing 15 SP2 LTSS	xen	Affected
SUSE Linux Enterprise High Performance Computing 15 SP3	xen	Affected
SUSE Linux Enterprise High Performance Computing 15 SP4	xen	Not affected
SUSE Linux Enterprise Micro 5.0	xen	Affected
SUSE Linux Enterprise Micro 5.1	xen	Affected
SUSE Linux Enterprise Micro 5.2	xen	Affected
SUSE Linux Enterprise Module for Basesystem 15 SP2	xen	Affected
SUSE Linux Enterprise Module for Basesystem 15 SP3	xen	Affected
SUSE Linux Enterprise Module for Basesystem 15 SP4	xen	Not affected
SUSE Linux Enterprise Module for Server Applications 15 SP2	xen	Affected
SUSE Linux Enterprise Module for Server Applications 15 SP3	xen	Affected
SUSE Linux Enterprise Module for Server Applications 15 SP4	xen	Not affected
SUSE Linux Enterprise Point of Service 11 SP3	xen	Unsupported
SUSE Linux Enterprise Real Time 15 SP2	xen	Affected
SUSE Linux Enterprise Server 11 SP1	xen	Unsupported
SUSE Linux Enterprise Server 11 SP3	xen	Unsupported
SUSE Linux Enterprise Server 11 SP4 LTSS	xen	Unsupported
SUSE Linux Enterprise Server 12 SP2 BCL	xen	Affected
SUSE Linux Enterprise Server 12 SP3 BCL	xen	Affected
SUSE Linux Enterprise Server 12 SP3 ESPOS	xen	Affected
SUSE Linux Enterprise Server 12 SP3 LTSS	xen	Affected
SUSE Linux Enterprise Server 12 SP4 ESPOS	xen	Released
SUSE Linux Enterprise Server 12 SP4 LTSS	xen	Released
SUSE Linux Enterprise Server 12 SP5	xen	Affected
SUSE Linux Enterprise Server 15 ESPOS	xen	Affected
SUSE Linux Enterprise Server 15 LTSS	xen	Affected
SUSE Linux Enterprise Server 15 SP1 LTSS	xen	Affected
SUSE Linux Enterprise Server 15 SP2	xen	Affected
SUSE Linux Enterprise Server 15 SP2 LTSS	xen	Affected
SUSE Linux Enterprise Server 15 SP3	xen	Affected
SUSE Linux Enterprise Server 15 SP4	xen	Not affected
SUSE Linux Enterprise Server Business Critical Linux 15 SP1	xen	Affected
SUSE Linux Enterprise Server Business Critical Linux 15 SP2	xen	Affected
SUSE Linux Enterprise Server for SAP Applications 12 SP3	xen	Affected
SUSE Linux Enterprise Server for SAP Applications 12 SP4	xen	Released
SUSE Linux Enterprise Server for SAP Applications 12 SP5	xen	Affected
SUSE Linux Enterprise Server for SAP Applications 15	xen	Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP1	xen	Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP2	xen	Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP3	xen	Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP4	xen	Not affected
SUSE Linux Enterprise Storage 7	xen	Affected
SUSE Linux Enterprise Storage 7.1	xen	Affected
SUSE Manager Proxy 4.0	xen	Unsupported
SUSE Manager Proxy 4.1	xen	Affected
SUSE Manager Proxy 4.2	xen	Affected
SUSE Manager Proxy 4.3	xen	Not affected
SUSE Manager Retail Branch Server 4.0	xen	Unsupported
SUSE Manager Retail Branch Server 4.1	xen	Affected
SUSE Manager Retail Branch Server 4.2	xen	Affected
SUSE Manager Retail Branch Server 4.3	xen	Not affected
SUSE Manager Server 4.0	xen	Unsupported
SUSE Manager Server 4.1	xen	Affected
SUSE Manager Server 4.2	xen	Affected
SUSE Manager Server 4.3	xen	Not affected
SUSE OpenStack Cloud 8	xen	Affected
SUSE OpenStack Cloud 9	xen	Released
SUSE OpenStack Cloud Crowbar 8	xen	Affected
SUSE OpenStack Cloud Crowbar 9	xen	Released