CVE-2024-31144

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.

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.

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.

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.

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.

Double unlock in x86 guest IRQ handling. (CVE-2024-31143) Xapi: Metadata injection attack against backup/restore functionality. (CVE-2024-31144) Error handling in x86 IOMMU identity mapping. (CVE-2024-31145) PCI device pass-through with shared resources. (CVE-2024-31146) x86: Deadlock in vlapic_error(). (CVE-2024-45817) Deadlock in x86 HVM standard VGA handling. (CVE-2024-45818) libxl leaks data to PVH guests via ACPI tables. (CVE-2024-45819) Backend can crash Linux netfront. (CVE-2024-53240) Xen hypercall page unsafe against speculative attacks. (CVE-2024-53241) Deadlock potential with VT-d and legacy PCI device pass-through. (CVE-2025-1713) x86: Indirect Target Selection. (CVE-2024-28956) x86: Incorrect stubs exception handling for flags recovery. (CVE-2025-27465) TSA-SQ (TSA in the Store Queues). (CVE-2024-36350) TSA-L1 (TSA in the L1 data cache). (CVE-2024-36357) A NULL pointer dereference in the updating of the reference TSC area. (CVE-2025-27466) A NULL pointer dereference by assuming the SIM page is mapped when a synthetic timer message has to be delivered. (CVE-2025-58142) A race in the mapping of the reference TSC page, where a guest can get Xen to free a page while still present in the guest physical to machine (p2m) page tables. (CVE-2025-58143) An assertion is wrong there, where the case actually needs handling. A NULL pointer de-reference could result on a release build. (CVE-2025-58144) The P2M lock isn't held until a page reference was actually obtained (or the attempt to do so has failed). Otherwise the page can not only change type, but even ownership in between, thus allowing domain boundaries to be violated. (CVE-2025-58145) XAPI UTF-8 string handling. (CVE-2025-58146) Hypercalls using the HV_VP_SET Sparse format can cause vpmask_set() to write out of bounds when converting the bitmap to Xen's format. (CVE-2025-58147) Hypercalls using any input format can cause send_ipi() to read d->vcpu[] out-of-bounds, and operate on a wild vCPU pointer.(CVE-2025-58148) Incorrect removal of permissions on PCI device unplug. (CVE-2025-58149)