CVE-2020-14339
Description
A flaw was found in libvirt, where it leaked a file descriptor for /dev/mapper/control into the QEMU process. This file descriptor allows for privileged operations to happen against the device-mapper on the host. This flaw allows a malicious guest user or process to perform operations outside of their standard permissions, potentially causing serious damage to the host operating system. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Statement
This flaw was introduced in libvirt version 6.2.0. Red Hat Enterprise Linux 5, 6, 7, and 8 are not affected by this issue as they shipped an older version of the libvirt package which did not include the vulnerable code.
This issue affects versions of the libvirt package as shipped with Red Hat Enterprise Linux Advanced Virtualization 8. Future libvirt package updates for Red Hat Enterprise Linux Advanced Virtualization 8 may address this issue.
Mitigation
This issue is mitigated on Red Hat Enterprise Linux if SELinux is in enforcing mode, which prevents the `/dev/mapper/control` file descriptor from being accessible by a guest user/process.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.8 | 8.8 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Changed | Changed | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (Other); DoS: Resource Consumption (Memory); DoS: Resource Consumption (CPU)
An attacker that can influence the allocation of resources that are not properly released could deplete the available resource pool and prevent all other processes from accessing the same type of resource. Frequently-affected resources include memory, CPU, disk space, power or battery, etc.
Acknowledgements
This issue was discovered by Daniel Berrange (Red Hat).
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