CVE-2021-4158: Null Pointer Dereference
A NULL pointer dereference issue was found in the ACPI code of QEMU. A malicious, privileged user within the guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition.
Other sources
A NULL pointer dereference was found in the ACPI code of QEMU. The flaw lies in hw/acpi/pcihp.c in pciwrite() where the bus pointer is used without checking if it's NULL, probably because an invalid selector was supplied. A malicious privileged user within the guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition.
Upstream issue: https://gitlab.com/qemu-project/qemu/-/issues/770
Upstream patch: https://lists.nongnu.org/archive/html/qemu-devel/2021-12/msg01491.html
— Red Hat
Affected Software
Remediation
Information
Patch Available
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is the vulnerability ID for this issue?
The vulnerability ID for this issue is CVE-2021-4158.
What is the severity of CVE-2021-4158?
The severity of CVE-2021-4158 is medium.
What is the affected software for CVE-2021-4158?
The affected software for CVE-2021-4158 includes Red Hat Enterprise Linux 9.0, qemu-kvm 17:7.0.0-13.el9, Ubuntu qemu 1:6.2+dfsg-2ubuntu5, and Ubuntu qemu 1:6.0+dfsg-2.
How can a malicious user exploit CVE-2021-4158?
A malicious, privileged user within the guest can exploit CVE-2021-4158 to crash the QEMU process on the host, resulting in a denial of service condition.
Is there a remedy available for CVE-2021-4158?
Yes, there are remedies available for CVE-2021-4158. Please refer to the official documentation and updates provided by your software vendor for the specific package versions mentioned.