Xen vulnerabilities, page 2
477 vulnerabilities
Known vulnerabilities in Xen products, newest first, with CVSS severity, EPSS, KEV listings and ransomware use, across 8 products.
PrioritiseCVE-2025-58145xen +3 moreArm issues with page refcounting[This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
There are two issues related to the mapping of pages belonging to other
domains: For one, an assertion is wrong there, where the case actually
needs handling. A NULL pointer de-reference could result on a release
build. This is CVE-2025-58144.
And then 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. This is CVE-2025-58145.CVSS7.5HighEPSS0.37%PrioritiseCVE-2025-58144xen +3 moreArm issues with page refcounting[This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
There are two issues related to the mapping of pages belonging to other
domains: For one, an assertion is wrong there, where the case actually
needs handling. A NULL pointer de-reference could result on a release
build. This is CVE-2025-58144.
And then 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. This is CVE-2025-58145.CVSS7.5HighEPSS0.47%PrioritiseCVE-2025-58143xen +3 moreMutiple vulnerabilities in the Viridian interface[This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
There are multiple issues related to the handling and accessing of guest
memory pages in the viridian code:
1. A NULL pointer dereference in the updating of the reference TSC area.
This is CVE-2025-27466.
2. A NULL pointer dereference by assuming the SIM page is mapped when
a synthetic timer message has to be delivered. This is
CVE-2025-58142.
3. 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. This is CVE-2025-58143.CVSS9.8CriticalEPSS0.38%PrioritiseCVE-2025-58142xen +3 moreMutiple vulnerabilities in the Viridian interface[This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
There are multiple issues related to the handling and accessing of guest
memory pages in the viridian code:
1. A NULL pointer dereference in the updating of the reference TSC area.
This is CVE-2025-27466.
2. A NULL pointer dereference by assuming the SIM page is mapped when
a synthetic timer message has to be delivered. This is
CVE-2025-58142.
3. 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. This is CVE-2025-58143.CVSS9.8CriticalEPSS0.48%PrioritiseCVE-2025-27466xen +3 moreMutiple vulnerabilities in the Viridian interface[This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]
There are multiple issues related to the handling and accessing of guest
memory pages in the viridian code:
1. A NULL pointer dereference in the updating of the reference TSC area.
This is CVE-2025-27466.
2. A NULL pointer dereference by assuming the SIM page is mapped when
a synthetic timer message has to be delivered. This is
CVE-2025-58142.
3. 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. This is CVE-2025-58143.CVSS9.8CriticalEPSS0.48%PrioritiseCVE-2025-1713xen +7 moredeadlock potential with VT-d and legacy PCI device pass-throughWhen setting up interrupt remapping for legacy PCI(-X) devices,
including PCI(-X) bridges, a lookup of the upstream bridge is required.
This lookup, itself involving acquiring of a lock, is done in a context
where acquiring that lock is unsafe. This can lead to a deadlock.CVSS7.5HighEPSS0.86%RoutineCVE-2025-27465xen +6 morex86: Incorrect stubs exception handling for flags recoveryCertain instructions need intercepting and emulating by Xen. In some
cases Xen emulates the instruction by replaying it, using an executable
stub. Some instructions may raise an exception, which is supposed to be
handled gracefully. Certain replayed instructions have additional logic
to set up and recover the changes to the arithmetic flags.
For replayed instructions where the flags recovery logic is used, the
metadata for exception handling was incorrect, preventing Xen from
handling the the exception gracefully, treating it as fatal instead.CVSS4.3MediumEPSS0.70%RoutineCVE-2024-31144xen · xapi +1 moreXapi: Metadata injection attack against backup/restore functionalityFor 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.CVSS3.8LowEPSS0.21%RoutineCVE-2024-2201xen +121 moreCVE-2024-2201A cross-privilege Spectre v2 vulnerability allows attackers to bypass all deployed mitigations, including the recent Fine(IBT), and to leak arbitrary Linux kernel memory on Intel systems.CVSS4.7MediumEPSS8.79%RoutineCVE-2024-45819xen +3 morelibxl leaks data to PVH guests via ACPI tablesPVH guests have their ACPI tables constructed by the toolstack. The
construction involves building the tables in local memory, which are
then copied into guest memory. While actually used parts of the local
memory are filled in correctly, excess space that is being allocated is
left with its prior contents.CVSS5.5MediumEPSS0.30%RoutineCVE-2024-45818xen +3 moreDeadlock in x86 HVM standard VGA handlingThe hypervisor contains code to accelerate VGA memory accesses for HVM
guests, when the (virtual) VGA is in "standard" mode. Locking involved
there has an unusual discipline, leaving a lock acquired past the
return from the function that acquired it. This behavior results in a
problem when emulating an instruction with two memory accesses, both of
which touch VGA memory (plus some further constraints which aren't
relevant here). When emulating the 2nd access, the lock that is already
being held would be attempted to be re-acquired, resulting in a
deadlock.
This deadlock was already found when the code was first introduced, but
was analysed incorrectly and the fix was incomplete. Analysis in light
of the new finding cannot find a way to make the existing locking
discipline work.
In staging, this logic has all been removed because it was discovered
to be accidentally disabled since Xen 4.7. Therefore, we are fixing the
locking problem by backporting the removal of most of the feature. Note
that even with the feature disabled, the lock would still be acquired
for any accesses to the VGA MMIO region.CVSS6.5MediumEPSS0.27%PrioritiseCVE-2024-45817xen +17 morex86: Deadlock in vlapic_error()In x86's APIC (Advanced Programmable Interrupt Controller) architecture,
error conditions are reported in a status register. Furthermore, the OS
can opt to receive an interrupt when a new error occurs.
It is possible to configure the error interrupt with an illegal vector,
which generates an error when an error interrupt is raised.
This case causes Xen to recurse through vlapic_error(). The recursion
itself is bounded; errors accumulate in the the status register and only
generate an interrupt when a new status bit becomes set.
However, the lock protecting this state in Xen will try to be taken
recursively, and deadlock.CVSS7.3HighEPSS0.54%RoutineCVE-2024-31146xen +2 morePCI device pass-through with shared resourcesWhen multiple devices share resources and one of them is to be passed
through to a guest, security of the entire system and of respective
guests individually cannot really be guaranteed without knowing
internals of any of the involved guests. Therefore such a configuration
cannot really be security-supported, yet making that explicit was so far
missing.
Resources the sharing of which is known to be problematic include, but
are not limited to
- - PCI Base Address Registers (BARs) of multiple devices mapping to the
same page (4k on x86),
- - INTx lines.CVSS7.5HighEPSS0.24%RoutineCVE-2024-31145xen +3 moreerror handling in x86 IOMMU identity mappingCertain PCI devices in a system might be assigned Reserved Memory
Regions (specified via Reserved Memory Region Reporting, "RMRR") for
Intel VT-d or Unity Mapping ranges for AMD-Vi. These are typically used
for platform tasks such as legacy USB emulation.
Since the precise purpose of these regions is unknown, once a device
associated with such a region is active, the mappings of these regions
need to remain continuouly accessible by the device. In the logic
establishing these mappings, error handling was flawed, resulting in
such mappings to potentially remain in place when they should have been
removed again. Respective guests would then gain access to memory
regions which they aren't supposed to have access to.CVSS7.5HighEPSS0.23%RoutineCVE-2024-31143xen +4 moredouble unlock in x86 guest IRQ handlingAn optional feature of PCI MSI called "Multiple Message" allows a
device to use multiple consecutive interrupt vectors. Unlike for MSI-X,
the setting up of these consecutive vectors needs to happen all in one
go. In this handling an error path could be taken in different
situations, with or without a particular lock held. This error path
wrongly releases the lock even when it is not currently held.CVSS7.5HighEPSS0.51%RoutineCVE-2024-31142fedoraproject · fedora +4 morex86: Incorrect logic for BTC/SRSO mitigationsBecause of a logical error in XSA-407 (Branch Type Confusion), the
mitigation is not applied properly when it is intended to be used.
XSA-434 (Speculative Return Stack Overflow) uses the same
infrastructure, so is equally impacted.
For more details, see:
https://xenbits.xen.org/xsa/advisory-407.html
https://xenbits.xen.org/xsa/advisory-434.htmlCVSS7.5HighEPSS17.44%RoutineCVE-2023-46842fedoraproject · fedora +4 morex86 HVM hypercalls may trigger Xen bug checkUnlike 32-bit PV guests, HVM guests may switch freely between 64-bit and
other modes. This in particular means that they may set registers used
to pass 32-bit-mode hypercall arguments to values outside of the range
32-bit code would be able to set them to.
When processing of hypercalls takes a considerable amount of time,
the hypervisor may choose to invoke a hypercall continuation. Doing so
involves putting (perhaps updated) hypercall arguments in respective
registers. For guests not running in 64-bit mode this further involves
a certain amount of translation of the values.
Unfortunately internal sanity checking of these translated values
assumes high halves of registers to always be clear when invoking a
hypercall. When this is found not to be the case, it triggers a
consistency check in the hypervisor and causes a crash.CVSS6.5MediumEPSS8.53%RoutineCVE-2023-46841fedoraproject · fedora +11 morex86: shadow stack vs exceptions from emulation stubsRecent x86 CPUs offer functionality named Control-flow Enforcement
Technology (CET). A sub-feature of this are Shadow Stacks (CET-SS).
CET-SS is a hardware feature designed to protect against Return Oriented
Programming attacks. When enabled, traditional stacks holding both data
and return addresses are accompanied by so called "shadow stacks",
holding little more than return addresses. Shadow stacks aren't
writable by normal instructions, and upon function returns their
contents are used to check for possible manipulation of a return address
coming from the traditional stack.
In particular certain memory accesses need intercepting by Xen. In
various cases the necessary emulation involves kind of replaying of
the instruction. Such replaying typically involves filling and then
invoking of a stub. Such a replayed instruction may raise an
exceptions, which is expected and dealt with accordingly.
Unfortunately the interaction of both of the above wasn't right:
Recovery involves removal of a call frame from the (traditional) stack.
The counterpart of this operation for the shadow stack was missing.CVSS6.5MediumEPSS0.27%RoutineCVE-2023-46840fedoraproject · fedora +4 moreVT-d: Failure to quarantine devices in !HVM buildsIncorrect placement of a preprocessor directive in source code results
in logic that doesn't operate as intended when support for HVM guests is
compiled out of Xen.CVSS4.1MediumEPSS0.26%RoutineCVE-2024-2193amd · cpu +163 moreSpeculative Race Condition impacts modern CPU architectures that support speculative execution, also known as GhostRace.A Speculative Race Condition (SRC) vulnerability that impacts modern CPU architectures supporting speculative execution (related to Spectre V1) has been disclosed. An unauthenticated attacker can exploit this vulnerability to disclose arbitrary data from the CPU using race conditions to access the speculative executable code paths.CVSS5.7MediumEPSS1.28%