Ubuntu update for libvirt

Published: 2022-05-03

Risk	Medium
Patch available	YES
Number of vulnerabilities	6
CVE-ID	CVE-2020-25637 CVE-2021-3631 CVE-2021-3667 CVE-2021-3975 CVE-2021-4147 CVE-2022-0897
CWE-ID	CWE-415 CWE-732 CWE-667 CWE-416
Exploitation vector	Network
Public exploit	Public exploit code for vulnerability #1 is available.
Vulnerable software	Ubuntu Operating systems & Components / Operating system libvirt0 (Ubuntu package) Operating systems & Components / Operating system package or component libvirt-daemon-system (Ubuntu package) Operating systems & Components / Operating system package or component libvirt-daemon (Ubuntu package) Operating systems & Components / Operating system package or component
Vendor	Canonical Ltd.

Security Bulletin

This security bulletin contains information about 6 vulnerabilities.

1) Double Free

EUVDB-ID: #VU48591

Risk: Low

CVSSv4.0: 7.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2020-25637

CWE-ID: CWE-415 - Double Free

Exploit availability: Yes

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error in the libvirt API, responsible for requesting information about network interfaces of a running QEMU domain. A local client connecting to the read-write socket with limited ACL permissions could use this flaw to crash the libvirt daemon, resulting in a denial of service, or potentially escalate their privileges on the system.

Mitigation

Update the affected package libvirt to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 21.10

libvirt0 (Ubuntu package): before 4.0.0-1ubuntu8.21

libvirt-daemon-system (Ubuntu package): before 4.0.0-1ubuntu8.21

libvirt-daemon (Ubuntu package): before 4.0.0-1ubuntu8.21

CPE2.3

External links

https://ubuntu.com/security/notices/USN-5399-1

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. However, proof of concept for this vulnerability is available.

2) Incorrect permission assignment for critical resource

EUVDB-ID: #VU62735

Risk: Medium

CVSSv4.0: 1.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-3631

CWE-ID: CWE-732 - Incorrect Permission Assignment for Critical Resource

Exploit availability: No

Description

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to an error in the way SELinux MCS category pairs for VMs' dynamic labels in security/security_selinux.c. An attacker with access to the guest OS can access files labeled for another guest.

Mitigation

Update the affected package libvirt to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 21.10

libvirt0 (Ubuntu package): before 4.0.0-1ubuntu8.21

libvirt-daemon-system (Ubuntu package): before 4.0.0-1ubuntu8.21

libvirt-daemon (Ubuntu package): before 4.0.0-1ubuntu8.21

CPE2.3

External links

https://ubuntu.com/security/notices/USN-5399-1

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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

3) Improper locking

EUVDB-ID: #VU62734

Risk: Low

CVSSv4.0: 1.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-3667

CWE-ID: CWE-667 - Improper Locking

Exploit availability: No

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 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.

Mitigation

Update the affected package libvirt to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 21.10

libvirt0 (Ubuntu package): before 4.0.0-1ubuntu8.21

libvirt-daemon-system (Ubuntu package): before 4.0.0-1ubuntu8.21

libvirt-daemon (Ubuntu package): before 4.0.0-1ubuntu8.21

CPE2.3

External links

https://ubuntu.com/security/notices/USN-5399-1

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.

4) Use-after-free

EUVDB-ID: #VU58358

Risk: Low

CVSSv4.0: 0.4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-3975

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

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

The vulnerability exists due to a use-after-free error in the qemuMonitorUnregister() function in qemuProcessHandleMonitorEOF. An unprivileged client with a read-only connection can trigger the use-after-free error by calling the virConnectGetAllDomainStats API and crash the application.

Mitigation

Update the affected package libvirt to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 21.10

libvirt0 (Ubuntu package): before 4.0.0-1ubuntu8.21

libvirt-daemon-system (Ubuntu package): before 4.0.0-1ubuntu8.21

libvirt-daemon (Ubuntu package): before 4.0.0-1ubuntu8.21

CPE2.3

External links

https://ubuntu.com/security/notices/USN-5399-1

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.

5) Improper locking

EUVDB-ID: #VU62737

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 - Improper Locking

Exploit availability: No

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

Update the affected package libvirt to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 21.10

libvirt0 (Ubuntu package): before 4.0.0-1ubuntu8.21

libvirt-daemon-system (Ubuntu package): before 4.0.0-1ubuntu8.21

libvirt-daemon (Ubuntu package): before 4.0.0-1ubuntu8.21

CPE2.3

External links

https://ubuntu.com/security/notices/USN-5399-1

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.

6) Improper locking

EUVDB-ID: #VU62739

Risk: Medium

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2022-0897

CWE-ID: CWE-667 - Improper Locking

Exploit availability: No

Description

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

The vulnerability exists due to double-locking error within the nwfilterConnectNumOfNWFilters() function in nwfilter/nwfilter_driver.c in libvirt. An local user can abuse the libvirt API virConnectNumOfNWFilters to crash the network filter management daemon (libvirtd/virtnwfilterd).

Mitigation

Update the affected package libvirt to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 21.10

libvirt0 (Ubuntu package): before 4.0.0-1ubuntu8.21

libvirt-daemon-system (Ubuntu package): before 4.0.0-1ubuntu8.21

libvirt-daemon (Ubuntu package): before 4.0.0-1ubuntu8.21

CPE2.3

External links

https://ubuntu.com/security/notices/USN-5399-1

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.