Vulnerability Description
An issue was discovered in Xen through 4.12.x allowing attackers to gain host OS privileges via DMA in a situation where an untrusted domain has access to a physical device. This occurs because passed through PCI devices may corrupt host memory after deassignment. When a PCI device is assigned to an untrusted domain, it is possible for that domain to program the device to DMA to an arbitrary address. The IOMMU is used to protect the host from malicious DMA by making sure that the device addresses can only target memory assigned to the guest. However, when the guest domain is torn down, or the device is deassigned, the device is assigned back to dom0, thus allowing any in-flight DMA to potentially target critical host data. An untrusted domain with access to a physical device can DMA into host memory, leading to privilege escalation. Only systems where guests are given direct access to physical devices capable of DMA (PCI pass-through) are vulnerable. Systems which do not use PCI pass-through are not vulnerable.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Xen | Xen | <= 4.12.1 |
| Debian | Debian Linux | 9.0 |
| Fedoraproject | Fedora | 29 |
| Opensuse | Leap | 15.0 |
Related Weaknesses (CWE)
References
- http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.htmlMailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2019/10/31/6Mailing ListMitigationThird Party Advisory
- http://xenbits.xen.org/xsa/advisory-302.htmlMitigationPatchVendor Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://seclists.org/bugtraq/2020/Jan/21Mailing ListThird Party Advisory
- https://security.gentoo.org/glsa/202003-56Third Party Advisory
- https://www.debian.org/security/2020/dsa-4602Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.htmlMailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2019/10/31/6Mailing ListMitigationThird Party Advisory
- http://xenbits.xen.org/xsa/advisory-302.htmlMitigationPatchVendor Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
FAQ
What is CVE-2019-18424?
CVE-2019-18424 is a vulnerability with a CVSS score of 6.8 (MEDIUM). An issue was discovered in Xen through 4.12.x allowing attackers to gain host OS privileges via DMA in a situation where an untrusted domain has access to a physical device. This occurs because passed...
How severe is CVE-2019-18424?
CVE-2019-18424 has been rated MEDIUM with a CVSS base score of 6.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2019-18424?
Check the references section above for vendor advisories and patch information. Affected products include: Xen Xen, Debian Debian Linux, Fedoraproject Fedora, Opensuse Leap.