CVE-2021-3308
What it is
An issue was discovered in Xen 4.12.3 through 4.12.4 and 4.13.1 through 4.14.x. An x86 HVM guest with PCI pass through devices can force the allocation of all IDT vectors on the system by rebooting itself with MSI or MSI-X capabilities enabled and entries setup. Such reboots will leak any vectors used by the MSI(-X) entries that the guest might had enabled, and hence will lead to vector exhaustion on the system, not allowing further PCI pass through devices to work properly. HVM guests with PCI pass through devices can mount a Denial of Service (DoS) attack affecting the pass through of PCI devices to other guests or the hardware domain. In the latter case, this would affect the entire host.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.4% 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: 0.4% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.4% · EPSS, next 30 days
- Record status
- Modified
Affected
- Xen ≤ 4.14.1
- Xen 4.12.3
- Xen 4.12.4
- Fedoraproject Fedora 32
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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-2021-3308.md and follow it. Check whether this project is affected by CVE-2021-3308. 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://www.openwall.com/lists/oss-security/2021/01/26/4
- http://xenbits.xen.org/xsa/advisory-360.html
- http://www.openwall.com/lists/oss-security/2021/01/26/4
- http://xenbits.xen.org/xsa/advisory-360.html
References
- http://www.openwall.com/lists/oss-security/2021/01/26/4
- http://xenbits.xen.org/xsa/advisory-360.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/S5C42TMQYB6SDVT2MPFEWY65A6RSUVBN/
- https://security.gentoo.org/glsa/202107-30
- http://www.openwall.com/lists/oss-security/2021/01/26/4
- http://xenbits.xen.org/xsa/advisory-360.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/S5C42TMQYB6SDVT2MPFEWY65A6RSUVBN/
- https://security.gentoo.org/glsa/202107-30