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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. An…
Medium5.5EPSS 0.39%
- Published
- Updated
- Reserved
- Assigned by
- redhat
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.39% · top 67% of all CVEs (6 Nov 2026)
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The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Weakness
Affected products
kernel
- affected Linux kernel versions prior to 5.17-rc1
References (4)
- [oss-security] 20220117 Re: CVE-2021-4095: kernel: KVM: NULL pointer dereference in kvm_dirty_ring_get() in virt/kvm/dirty_ring.c (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- https://bugzilla.redhat.com/show_bug.cgi?id=2031194 (opens in a new tab)x_refsource_MISCx_transferred
- FEDORA-2022-0816754490 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2022-8efcea6e67 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2021-4095)Record last updated .