Is CVE-2021-3559 actively exploited?

No active exploitation of CVE-2021-3559 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-3559 be exploited remotely?

Yes. CVE-2021-3559 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-3559?

CVE-2021-3559 has a CVSS score of 6.5 (MEDIUM).

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MEDIUM

CVE-2021-3559

CWE-119Published: May 24, 2021· Updated: Jun 17, 2026

6.5

CVSS v3.1

Official Description

A flaw was found in libvirt in the virConnectListAllNodeDevices API in versions before 7.0.0. It only affects hosts with a PCI device and driver that supports mediated devices (e.g., GRID driver). This flaw could be used by an unprivileged client with a read-only connection to crash the libvirt daemon by executing the 'nodedev-list' virsh command. The highest threat from this vulnerability is to system availability.

NVD Source

Technical Analysis

CVE-2021-3559 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 6.5.

From a weakness classification perspective (CWE-119): Buffer overflow vulnerabilities can lead to arbitrary code execution or denial of service by corrupting adjacent memory.