CVE-2021-3667

An improper locking issue was found in the virStoragePoolLookupByTargetPath API of libvirt. It occurs in the storagePoolLookupByTargetPath function where a locked virStoragePoolObj object is not properly released on ACL permission failure. Clients connecting to the read-write socket with limited ACL permissions could use this flaw to acquire the lock and prevent other users from accessing storage pool/volume APIs, resulting in a denial of service condition. The highest threat from this vulnerability is to system availability.

Published: 2022-03-02 Last update: 2025-02-10 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3667 is rated Moderate Risk (50.5/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.34%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-3667

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.44% 1.34% +0.90%
2 2025-12-11 0.28% 0.44% +0.16%
3 2025-11-21 — 0.28% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3667

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]
3.5 2.0 LOW
AV:N/AC:M/Au:S/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 6.8 2.9 [email protected]

Weakness enumeration for CVE-2021-3667

OS Trackers for CVE-2021-3667

vendor priority summary link
alpine — CVE-2021-3667: 1 source package rows (libvirt); 9 state rows across 3 repos (3.12-main, 3.22-community, edge-community); fixed 0, open 9. https://security.alpinelinux.org/vuln/CVE-2021-3667
debian not yet assigned CVE-2021-3667 not yet assigned priority: Debian including 1 source packages (libvirt), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-3667
gentoo low CVE-2021-3667: 1 GLSA(s) (202210-06), 2 atom(s) (app-emulation/libvirt, dev-python/libvirt-python); latest impact low. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-3667
redhat low — https://access.redhat.com/security/cve/CVE-2021-3667
suse medium CVE-2021-3667 severity moderate: SUSE including 693 source package names (0.45.0.7.7.1:libvirt-libs-7.1.0-6.5.1, 0.45.0.8.14.1:libvirt-client-7.1.0-6.5.1, …), 1513 product×package rows across 79 product lines (Container suse/sles/15.3/libguestfs-tools, Container suse/sles/15.3/virt-handler, … (79 product lines)): Fixed 790, Known Not Affected 492, Known Affected 231. https://www.suse.com/security/cve/CVE-2021-3667/
ubuntu low CVE-2021-3667 low priority: Ubuntu including 1 source packages (libvirt), 8 status rows across 8 suites (bionic, focal, hirsute, impish, jammy, trusty, upstream, xenial): not-affected 4, released 3, ignored 1. https://ubuntu.com/security/CVE-2021-3667

Affected software / configurations for CVE-2021-3667

Vendor Product Version Raw CPE
redhat libvirt >= 4.1.0, <= 7.5.0 cpe:2.3:a:redhat:libvirt:*:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:advanced_virtualization:*:*:*
netapp ontap_select_deploy_administration_utility — cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2021-3667

cvelogic Threat Intelligence