CVE-2021-4095 — NULL Pointer Dereference in Linux

CWE-476 — NULL Pointer Dereference6 documents6 sources
Severity
5.5MEDIUMNVD
EPSS
0.1%
top 70.18%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
5
Linux KernelDebian LinuxFedoraproject Fedora+2 more
Timeline
PublishedMar 10
Latest updateMar 11

Description

A NULL pointer dereference was found in the Linux kernel's KVM when dirty ring logging is enabled without an active vCPU context. An unprivileged local attacker on the host may use this flaw to cause a kernel oops condition and thus a denial of service by issuing a KVM_XEN_HVM_SET_ATTR ioctl. This flaw affects Linux kernel versions prior to 5.17-rc1.

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitability: 1.8 | Impact: 3.6

Affected Packages6 packages

▶Debianlinux/linux_kernel< 5.17.3-1+2
▶CVEListV5linux/linux_kernelLinux kernel versions prior to 5.17-rc1

Also affects: Fedora 34, 35

Patches

Patch: www.openwall.com ↗Patch: bugzilla.redhat.com ↗Patch: www.openwall.com ↗

🔴Vulnerability Details

2
GHSA
GHSA-p8x3-xpch-p28r: A NULL pointer dereference was found in the Linux kernel's KVM when dirty ring logging is enabled without an active vCPU context↗2022-03-11
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OSV
CVE-2021-4095: A NULL pointer dereference was found in the Linux kernel's KVM when dirty ring logging is enabled without an active vCPU context↗2022-03-10
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📋Vendor Advisories

3
Microsoft
A NULL pointer dereference was found in the Linux kernel's KVM when dirty ring logging is enabled without an active vCPU context. An unprivileged local attacker on the host may use this flaw to cause ↗2022-03-08
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Red Hat
kernel: KVM: NULL pointer dereference in kvm_dirty_ring_get() in virt/kvm/dirty_ring.c↗2021-10-19
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Debian
CVE-2021-4095: linux - A NULL pointer dereference was found in the Linux kernel's KVM when dirty ring l...↗2021
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