Improper locking in libvirt

Published: 2022-05-03
Risk Low
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2021-3667
Exploitation vector Local
Public exploit N/A
Vulnerable software
Universal components / Libraries / Libraries used by multiple products


Security Bulletin

This security bulletin contains one low risk vulnerability.

1) Improper locking

EUVDB-ID: #VU62734

Risk: Low

CVSSv3.1: 2.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3667

CWE-ID: CWE-667 - Improper Locking

Exploit availability: No


The vulnerability allows a local user to perform a denial of service attack (DoS) on the target system.

The vulnerability exists due to double-locking error in the virStoragePoolLookupByTargetPath API in libvirt in storage/storage_driver.c. The storagePoolLookupByTargetPath() function does not properly release a locked object (virStoragePoolObj) on ACL permission failure. Clients connecting to the read-write socket with limited ACL permissions can use this vulnerability to acquire the lock and prevent other users from accessing storage pool/volume APIs. As a result a local user can perform a denial of service (DoS) attack.


Install updates from vendor's website.

Vulnerable software versions

libvirt: 4.1.0 - 7.5.0

CPE2.3 External links;a=commit;h=447f69dec47e1b0bd15ecd7cd49a9fd3b050fb87

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.