CVE-2024-31144

Xapi: Metadata injection attack against backup/restore functionality

Published Feb 14, 2025 CVSS 3.1 · 3.8 Low EPSS < 1% KEV · Not listed
Description
For a brief summary of Xapi terminology, see:

https://xapi-project.github.io/xen-api/overview.html#object-model-overview

Xapi contains functionality to backup and restore metadata about Virtual
Machines and Storage Repositories (SRs).

The metadata itself is stored in a Virtual Disk Image (VDI) inside an
SR. This is used for two purposes; a general backup of metadata
(e.g. to recover from a host failure if the filer is still good), and
Portable SRs (e.g. using an external hard drive to move VMs to another
host).

Metadata is only restored as an explicit administrator action, but
occurs in cases where the host has no information about the SR, and must
locate the metadata VDI in order to retrieve the metadata.

The metadata VDI is located by searching (in UUID alphanumeric order)
each VDI, mounting it, and seeing if there is a suitable metadata file
present. The first matching VDI is deemed to be the metadata VDI, and
is restored from.

In the general case, the content of VDIs are controlled by the VM owner,
and should not be trusted by the host administrator.

A malicious guest can manipulate its disk to appear to be a metadata
backup.

A guest cannot choose the UUIDs of its VDIs, but a guest with one disk
has a 50% chance of sorting ahead of the legitimate metadata backup. A
guest with two disks has a 75% chance, etc.

Remediation

Vendor Workaround

Not using the metadata restore functionality avoids the vulnerability.

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
EUVD EUVD EUVD-2024-29054 For a brief summary of Xapi terminology, see: https://xapi-project.github.io/xen-api/overview.html#object-model-overview Xapi contains functionality to backup and restore metadata about Virtual Machines and Storage Repositories (SRs). The metadata itself is stored in a Virtual Disk Image (VDI) inside an SR. This is used for two purposes; a general backup of metadata (e.g. to recover from a host failure if the filer is still good), and Portable SRs (e.g. using an external hard drive to move VMs to another host). Metadata is only restored as an explicit administrator action, but occurs in cases where the host has no information about the SR, and must locate the metadata VDI in order to retrieve the metadata. The metadata VDI is located by searching (in UUID alphanumeric order) each VDI, mounting it, and seeing if there is a suitable metadata file present. The first matching VDI is deemed to be the metadata VDI, and is restored from. In the general case, the content of VDIs are controlled by the VM owner, and should not be trusted by the host administrator. A malicious guest can manipulate its disk to appear to be a metadata backup. A guest cannot choose the UUIDs of its VDIs, but a guest with one disk has a 50% chance of sorting ahead of the legitimate metadata backup. A guest with two disks has a 75% chance, etc.
History
Type Values Removed Values Added
First Time appeared Xen
Xen xapi
Weaknesses CWE-829
CPEs cpe:2.3:o:xen:xapi:*:*:*:*:*:*:*:*
Vendors & Products Xen
Xen xapi
Type Values Removed Values Added
Metrics epss

{'score': 0.00019}

epss

{'score': 0.00021}

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 3.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description For a brief summary of Xapi terminology, see: https://xapi-project.github.io/xen-api/overview.html#object-model-overview Xapi contains functionality to backup and restore metadata about Virtual Machines and Storage Repositories (SRs). The metadata itself is stored in a Virtual Disk Image (VDI) inside an SR. This is used for two purposes; a general backup of metadata (e.g. to recover from a host failure if the filer is still good), and Portable SRs (e.g. using an external hard drive to move VMs to another host). Metadata is only restored as an explicit administrator action, but occurs in cases where the host has no information about the SR, and must locate the metadata VDI in order to retrieve the metadata. The metadata VDI is located by searching (in UUID alphanumeric order) each VDI, mounting it, and seeing if there is a suitable metadata file present. The first matching VDI is deemed to be the metadata VDI, and is restored from. In the general case, the content of VDIs are controlled by the VM owner, and should not be trusted by the host administrator. A malicious guest can manipulate its disk to appear to be a metadata backup. A guest cannot choose the UUIDs of its VDIs, but a guest with one disk has a 50% chance of sorting ahead of the legitimate metadata backup. A guest with two disks has a 75% chance, etc.
Title Xapi: Metadata injection attack against backup/restore functionality
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
XEN
Published
Updated
Apr 26, 2025, 8:03 PM
Reserved
Mar 28, 2024, 6:14 PM
Status
Analyzed
Published
Feb 14, 2025, 9:15 PM
Modified
Jun 17, 2026, 7:27 AM