CVE-2021-3975
What it is
A use-after-free flaw was found in libvirt. The qemuMonitorUnregister() function in qemuProcessHandleMonitorEOF is called using multiple threads without being adequately protected by a monitor lock. This flaw could be triggered by the virConnectGetAllDomainStats API when the guest is shutting down. An unprivileged client with a read-only connection could use this flaw to perform a denial of service attack by causing the libvirt daemon to crash.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of service disruption.
- Exploit odds
- 1.7% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 1.7% in the next 30 days (EPSS).
- Severity: 6.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 1.7% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Modified
Affected
- Redhat Libvirt < 7.1.0
- Canonical Ubuntu Linux 21.10
- Fedoraproject Fedora 35
- Redhat Enterprise Linux 8.0
- Redhat Enterprise Linux Eus 8.6
- Redhat Enterprise Linux For IBM Z Systems 8.0
- Redhat Enterprise Linux For IBM Z Systems Eus 8.6
- Redhat Enterprise Linux For Power Little Endian 8.0
Attack profile CVSS 3.1 · 6.5
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-3975.md and follow it. Check whether this project is affected by CVE-2021-3975. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://bugzilla.redhat.com/show_bug.cgi?id=2024326
- https://github.com/libvirt/libvirt/commit/1ac703a7d0789e46833f4013a3876c2e3af18ec7
- https://ubuntu.com/security/CVE-2021-3975
- https://bugzilla.redhat.com/show_bug.cgi?id=2024326
- https://github.com/libvirt/libvirt/commit/1ac703a7d0789e46833f4013a3876c2e3af18ec7
- https://ubuntu.com/security/CVE-2021-3975
References
- https://access.redhat.com/security/cve/CVE-2021-3975
- https://bugzilla.redhat.com/show_bug.cgi?id=2024326
- https://github.com/libvirt/libvirt/commit/1ac703a7d0789e46833f4013a3876c2e3af18ec7
- https://lists.debian.org/debian-lts-announce/2024/04/msg00000.html
- https://security.netapp.com/advisory/ntap-20221201-0002/
- https://ubuntu.com/security/CVE-2021-3975
- https://access.redhat.com/security/cve/CVE-2021-3975
- https://bugzilla.redhat.com/show_bug.cgi?id=2024326
- https://github.com/libvirt/libvirt/commit/1ac703a7d0789e46833f4013a3876c2e3af18ec7
- https://lists.debian.org/debian-lts-announce/2024/04/msg00000.html
- https://security.netapp.com/advisory/ntap-20221201-0002/
- https://ubuntu.com/security/CVE-2021-3975