#VU62737 Improper locking in libvirt - CVE-2021-4147

Vulnerability identifier: #VU62737

Vulnerability risk: Low

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-4147

CWE-ID: CWE-667

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
libvirt
Universal components / Libraries / Libraries used by multiple products

Vendor: libvirt.org

Description

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 libvirt libxl driver in libxl/libxl_domain.c. A malicious guest can continuously reboot itself and cause libvirtd on the host to deadlock or crash, resulting in a denial of service condition

Mitigation
Install updates from vendor's website.

Vulnerable software versions

libvirt: before 2.33.0

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=2034195

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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.