CVE-2025-21779
KVM Hyper-V Local APIC Vulnerability
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Reject Hyper-V's SEND_IPI hypercalls if local APIC isn't in-kernel Advertise support for Hyper-V's SEND_IPI and SEND_IPI_EX hypercalls if and only if the local API is emulated/virtualized by KVM, and explicitly reject said hypercalls if the local APIC is emulated in userspace, i.e. don't rely on userspace to opt-in to KVM_CAP_HYPERV_ENFORCE_CPUID. Rejecting SEND_IPI and SEND_IPI_EX fixes a NULL-pointer dereference if Hyper-V enlightenments are exposed to the guest without an in-kernel local APIC: dump_stack+0xbe/0xfd __kasan_report.cold+0x34/0x84 kasan_report+0x3a/0x50 __apic_accept_irq+0x3a/0x5c0 kvm_hv_send_ipi.isra.0+0x34e/0x820 kvm_hv_hypercall+0x8d9/0x9d0 kvm_emulate_hypercall+0x506/0x7e0 __vmx_handle_exit+0x283/0xb60 vmx_handle_exit+0x1d/0xd0 vcpu_enter_guest+0x16b0/0x24c0 vcpu_run+0xc0/0x550 kvm_arch_vcpu_ioctl_run+0x170/0x6d0 kvm_vcpu_ioctl+0x413/0xb20 __se_sys_ioctl+0x111/0x160 do_syscal1_64+0x30/0x40 entry_SYSCALL_64_after_hwframe+0x67/0xd1 Note, checking the sending vCPU is sufficient, as the per-VM irqchip_mode can't be modified after vCPUs are created, i.e. if one vCPU has an in-kernel local APIC, then all vCPUs have an in-kernel local APIC.
INFO
Published Date :
Feb. 27, 2025, 3:15 a.m.
Last Modified :
April 10, 2025, 1:15 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-21779.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-21779 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-21779 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 10, 2025
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/61224533f2b61e252b03e214195d27d64b22989a -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Mar. 13, 2025
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/45fa526b0f5a34492ed0536c3cdf88b78380e4de -
Initial Analysis by [email protected]
Mar. 05, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-476 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 from (excluding) 6.13.4 *cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 from (excluding) 6.6.79 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 from (excluding) 6.12.16 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.20 from (excluding) 6.1.129 Added Reference Type kernel.org: https://git.kernel.org/stable/c/5393cf22312418262679eaadb130d608c75fe690 Types: Mailing List, Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/874ff13c73c45ecb38cb82191e8c1d523f0dc81b Types: Mailing List, Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a8de7f100bb5989d9c3627d3a223ee1c863f3b69 Types: Mailing List, Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/aca8be4403fb90db7adaf63830e27ebe787a76e8 Types: Mailing List, Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/ca29f58ca374c40a0e69c5306fc5c940a0069074 Types: Mailing List, Patch -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Feb. 27, 2025
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Reject Hyper-V's SEND_IPI hypercalls if local APIC isn't in-kernel Advertise support for Hyper-V's SEND_IPI and SEND_IPI_EX hypercalls if and only if the local API is emulated/virtualized by KVM, and explicitly reject said hypercalls if the local APIC is emulated in userspace, i.e. don't rely on userspace to opt-in to KVM_CAP_HYPERV_ENFORCE_CPUID. Rejecting SEND_IPI and SEND_IPI_EX fixes a NULL-pointer dereference if Hyper-V enlightenments are exposed to the guest without an in-kernel local APIC: dump_stack+0xbe/0xfd __kasan_report.cold+0x34/0x84 kasan_report+0x3a/0x50 __apic_accept_irq+0x3a/0x5c0 kvm_hv_send_ipi.isra.0+0x34e/0x820 kvm_hv_hypercall+0x8d9/0x9d0 kvm_emulate_hypercall+0x506/0x7e0 __vmx_handle_exit+0x283/0xb60 vmx_handle_exit+0x1d/0xd0 vcpu_enter_guest+0x16b0/0x24c0 vcpu_run+0xc0/0x550 kvm_arch_vcpu_ioctl_run+0x170/0x6d0 kvm_vcpu_ioctl+0x413/0xb20 __se_sys_ioctl+0x111/0x160 do_syscal1_64+0x30/0x40 entry_SYSCALL_64_after_hwframe+0x67/0xd1 Note, checking the sending vCPU is sufficient, as the per-VM irqchip_mode can't be modified after vCPUs are created, i.e. if one vCPU has an in-kernel local APIC, then all vCPUs have an in-kernel local APIC. Added Reference https://git.kernel.org/stable/c/5393cf22312418262679eaadb130d608c75fe690 Added Reference https://git.kernel.org/stable/c/874ff13c73c45ecb38cb82191e8c1d523f0dc81b Added Reference https://git.kernel.org/stable/c/a8de7f100bb5989d9c3627d3a223ee1c863f3b69 Added Reference https://git.kernel.org/stable/c/aca8be4403fb90db7adaf63830e27ebe787a76e8 Added Reference https://git.kernel.org/stable/c/ca29f58ca374c40a0e69c5306fc5c940a0069074
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-21779 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-21779
weaknesses.