Alpine: multiple xen packages: security update to 4.15.1-r1

high Tenable Cloud Security Plugin ID 424670

Description

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

- PCI devices with RMRRs not deassigned correctly Certain PCI devices in a system might be assigned Reserved
Memory Regions (specified via Reserved Memory Region Reporting, "RMRR"). These are typically used for
platform tasks such as legacy USB emulation. If such a device is passed through to a guest, then on guest
shutdown the device is not properly deassigned. The IOMMU configuration for these devices which are not
properly deassigned ends up pointing to a freed data structure, including the IO Pagetables. Subsequent
DMA or interrupts from the device will have unpredictable behaviour, ranging from IOMMU faults to memory
corruption. (CVE-2021-28702)

- 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)

- certain VT-d IOMMUs may not work in shared page table mode For efficiency reasons, address translation
control structures (page tables) may (and, on suitable hardware, by default will) be shared between CPUs,
for second-level translation (EPT), and IOMMUs. These page tables are presently set up to always be 4
levels deep. However, an IOMMU may require the use of just 3 page table levels. In such a configuration
the lop level table needs to be stripped before inserting the root table's address into the hardware
pagetable base register. When sharing page tables, Xen erroneously skipped this stripping. Consequently,
the guest is able to write to leaf page table entries. (CVE-2021-28710)

Plugin Details

Severity: High

ID: 424670

Version: Revision 1.9

Type: Local

Family: Alpine Linux Local Security Checks

Published: 4/4/2025

Updated: 7/2/2026

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

Risk Information

VPR

Risk Factor: High

Score: 7

Percentile: 98.57

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-2021-28710

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

Vulnerability Information

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 8/5/2021

Reference Information

CVE: CVE-2021-28702, CVE-2021-28703, CVE-2021-28710

IAVB: 2021-B-0044-S, 2021-B-0068-S

Detections

Analytics