SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2022:3665-1)

high Nessus Plugin ID 166301

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Synopsis

The remote SUSE host is missing one or more security updates.

Description

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2022:3665-1 advisory.

- 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. (CVE-2021-28689)

- Linux disk/nic frontends data leaks T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Linux Block and Network PV device frontends don't zero memory regions before sharing them with the backend (CVE-2022-26365, CVE-2022-33740).
Additionally the granularity of the grant table doesn't allow sharing less than a 4K page, leading to unrelated data residing in the same 4K page as data shared with a backend being accessible by such backend (CVE-2022-33741, CVE-2022-33742). (CVE-2022-26365, CVE-2022-33740, CVE-2022-33741, CVE-2022-33742)

- insufficient TLB flush for x86 PV guests in shadow mode For migration as well as to work around kernels unaware of L1TF (see XSA-273), PV guests may be run in shadow paging mode. To address XSA-401, code was moved inside a function in Xen. This code movement missed a variable changing meaning / value between old and new code positions. The now wrong use of the variable did lead to a wrong TLB flush condition, omitting flushes where such are necessary. (CVE-2022-33745)

- P2M pool freeing may take excessively long The P2M pool backing second level address translation for guests may be of significant size. Therefore its freeing may take more time than is reasonable without intermediate preemption checks. Such checking for the need to preempt was so far missing. (CVE-2022-33746)

- lock order inversion in transitive grant copy handling As part of XSA-226 a missing cleanup call was inserted on an error handling path. While doing so, locking requirements were not paid attention to. As a result two cooperating guests granting each other transitive grants can cause locks to be acquired nested within one another, but in respectively opposite order. With suitable timing between the involved grant copy operations this may result in the locking up of a CPU. (CVE-2022-33748)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

Plugin Details

Severity: High

ID: 166301

File Name: suse_SU-2022-3665-1.nasl

Version: 1.6

Type: local

Agent: unix

Family: SuSE Local Security Checks

Published: 10/20/2022

Updated: 7/14/2023

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.5

CVSS v2

Risk Factor: Low

Base Score: 3.6

Temporal Score: 2.7

Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:P

CVSS Score Source: CVE-2022-33742

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS Score Source: CVE-2022-33745

Vulnerability Information

CPE: p-cpe:/a:novell:suse_linux:xen-tools-xendomains-wait-disk, p-cpe:/a:novell:suse_linux:xen-tools, p-cpe:/a:novell:suse_linux:xen, p-cpe:/a:novell:suse_linux:xen-libs, p-cpe:/a:novell:suse_linux:xen-tools-domu, p-cpe:/a:novell:suse_linux:xen-devel, cpe:/o:novell:suse_linux:15

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/SuSE/release, Host/SuSE/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 10/19/2022

Vulnerability Publication Date: 2/18/2021

Reference Information

CVE: CVE-2021-28689, CVE-2022-26365, CVE-2022-33740, CVE-2022-33741, CVE-2022-33742, CVE-2022-33745, CVE-2022-33746, CVE-2022-33748

IAVB: 2021-B-0011-S

SuSE: SUSE-SU-2022:3665-1

Detections

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