#VU104994 NULL pointer dereference in Linux kernel - CVE-2025-21779

Vulnerability identifier: #VU104994

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21779

CWE-ID: CWE-476

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to NULL pointer dereference within the kvm_hv_send_ipi() and kvm_get_hv_cpuid() functions in arch/x86/kvm/hyperv.c. A local user can perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 6.13, 6.13.1, 6.13.2, 6.13.3

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External links
https://git.kernel.org/stable/c/5393cf22312418262679eaadb130d608c75fe690
https://git.kernel.org/stable/c/874ff13c73c45ecb38cb82191e8c1d523f0dc81b
https://git.kernel.org/stable/c/a8de7f100bb5989d9c3627d3a223ee1c863f3b69
https://git.kernel.org/stable/c/aca8be4403fb90db7adaf63830e27ebe787a76e8
https://git.kernel.org/stable/c/ca29f58ca374c40a0e69c5306fc5c940a0069074
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.13.4

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.