CVE-2019-19579
What it is
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 (and assignable-add is not used), because of an incomplete fix for CVE-2019-18424. XSA-302 relies on the use of libxl's "assignable-add" feature to prepare devices to be assigned to untrusted guests. Unfortunately, this is not considered a strictly required step for device assignment. The PCI passthrough documentation on the wiki describes alternate ways of preparing devices for assignment, and libvirt uses its own ways as well. Hosts where these "alternate" methods are used will still leave the system in a vulnerable state after the device comes back from a guest. 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.
At a glance
- Exploitability
- Can be exploited with physical access without logging in. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.5% in the next 30 days (EPSS).
- Severity: 6.8 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Weakness
- CWE-20 · Improper input validation
- Record status
- Modified
Affected
- Xen ≤ 4.12.1
- Fedoraproject Fedora 30
Attack profile CVSS 3.1 · 6.8
- Attack vector
- Physical
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2019-19579.md and follow it. Check whether this project is affected by CVE-2019-19579. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- http://xenbits.xen.org/xsa/advisory-306.html
- https://xenbits.xen.org/xsa/advisory-306.html
- http://xenbits.xen.org/xsa/advisory-306.html
- https://xenbits.xen.org/xsa/advisory-306.html
References
- http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00011.html
- http://www.openwall.com/lists/oss-security/2019/12/05/7
- http://xenbits.xen.org/xsa/advisory-306.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJYT5FNGM7JSVHHW6B22TSAATBOAPFPD/
- https://seclists.org/bugtraq/2020/Jan/21
- https://www.debian.org/security/2020/dsa-4602
- https://www.openwall.com/lists/oss-security/2019/11/26/2
- https://xenbits.xen.org/xsa/advisory-306.html
- http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00011.html
- http://www.openwall.com/lists/oss-security/2019/12/05/7
- http://xenbits.xen.org/xsa/advisory-306.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJYT5FNGM7JSVHHW6B22TSAATBOAPFPD/
- https://seclists.org/bugtraq/2020/Jan/21
- https://www.debian.org/security/2020/dsa-4602
- https://www.openwall.com/lists/oss-security/2019/11/26/2
- https://xenbits.xen.org/xsa/advisory-306.html