CVE-2021-3308: Medium severity XEN Xen vulnerability
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.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2021-3308?
CVE-2021-3308 has been assigned a medium severity rating due to its potential impact on system resources.
How do I fix CVE-2021-3308?
To fix CVE-2021-3308, users should update to the latest version of Xen that addresses this vulnerability.
What versions of Xen are affected by CVE-2021-3308?
CVE-2021-3308 affects Xen versions 4.12.3, 4.12.4, and from 4.13.1 to 4.14.x.
Can CVE-2021-3308 be exploited remotely?
CVE-2021-3308 requires local access by an x86 HVM guest to exploit, so it is not considered a remote vulnerability.
What are the implications of CVE-2021-3308 for system administrators?
System administrators should be aware that CVE-2021-3308 can lead to resource exhaustion on the host if exploited, necessitating prompt updates.