Detections
Analytics
Alpine: xen: security update to 4.13.4-r0
high Tenable Cloud Security Plugin ID 407784
Description
There are packages installed that are affected by a vulnerability referenced in the following CVE:- 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)
See Also
Plugin Details
Severity: High
ID: 407784
Version: Revision 1.32
Type: Local
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
Temporal Score: 6.1
Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/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: 12/2/2021
Reference Information
CVE: CVE-2021-28703
IAVB: 2021-B-0068-S