Alpine: xen: security update to 4.14.5-r0

high Tenable Cloud Security Plugin ID 407800

Description

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

- grant table v2 status pages may remain accessible after de-allocation (take two) Guest get permitted
access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with
a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest
switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the
guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests
from the guest to insert mappings of these pages may result in any of them to become mapped in multiple
locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed
and perhaps re-used for other purposes. This bug was fortuitously fixed by code cleanup in Xen 4.14, and
backported to security-supported Xen branches as a prerequisite of the fix for XSA-378. (CVE-2021-28703)

- guests may exceed their designated memory limit When a guest is permitted to have close to 16TiB of
memory, it may be able to issue hypercalls to increase its memory allocation beyond the administrator
established limit. This is a result of a calculation done with 32-bit precision, which may overflow. It
would then only be the overflowed (and hence small) number which gets compared against the established
upper bound. (CVE-2021-28706)

- arm: guest_physmap_remove_page not removing the p2m mappings The functions to remove one or more entries
from a guest p2m pagetable on Arm (p2m_remove_mapping, guest_physmap_remove_page, and p2m_set_entry with
mfn set to INVALID_MFN) do not actually clear the pagetable entry if the entry doesn't have the valid bit
set. It is possible to have a valid pagetable entry without the valid bit set when a guest operating
system uses set/way cache maintenance instructions. For instance, a guest issuing a set/way cache
maintenance instruction, then calling the XENMEM_decrease_reservation hypercall to give back memory pages
to Xen, might be able to retain access to those pages even after Xen started reusing them for other
purposes. (CVE-2022-23033)

- A PV guest could DoS Xen while unmapping a grant To address XSA-380, reference counting was introduced for
grant mappings for the case where a PV guest would have the IOMMU enabled. PV guests can request two forms
of mappings. When both are in use for any individual mapping, unmapping of such a mapping can be requested
in two steps. The reference count for such a mapping would then mistakenly be decremented twice. Underflow
of the counters gets detected, resulting in the triggering of a hypervisor bug check. (CVE-2022-23034)

Plugin Details

Severity: High

ID: 407800

Version: Revision 1.26

Type: Local

Family: Alpine Linux Local Security Checks

Published: 10/31/2023

Updated: 7/2/2026

Supported Sensors: Agentless Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 97.36

CVSS v2

Risk Factor: Medium

Base Score: 6.9

Temporal Score: 5.1

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

CVSS Score Source: CVE-2021-28703

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

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

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

CVSS Score Source: CVE-2022-26361

Vulnerability Information

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 11/24/2021

Reference Information

CVE: CVE-2021-28703, CVE-2021-28706, CVE-2022-23033, CVE-2022-23034, CVE-2022-23035, CVE-2022-26356, CVE-2022-26357, CVE-2022-26358, CVE-2022-26359, CVE-2022-26360, CVE-2022-26361

IAVB: 2021-B-0068-S

Detections

Analytics