CVE-2021-28710: High severity xen xapi vulnerability
certain VT-d IOMMUs may not work in shared page table mode For efficiency reasons, address translation control structures (page tables) may (and, on suitable hardware, by default will) be shared between CPUs, for second-level translation (EPT), and IOMMUs. These page tables are presently set up to always be 4 levels deep. However, an IOMMU may require the use of just 3 page table levels. In such a configuration the lop level table needs to be stripped before inserting the root table's address into the hardware pagetable base register. When sharing page tables, Xen erroneously skipped this stripping. Consequently, the guest is able to write to leaf page table entries.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2021-28710?
CVE-2021-28710 has a medium severity level due to potential impacts on IOMMU functionality in shared page table mode.
How do I fix CVE-2021-28710?
To address CVE-2021-28710, ensure that you update to the patched versions of Xen or Fedora as recommended in the security advisories.
Which software versions are affected by CVE-2021-28710?
CVE-2021-28710 affects Xen version 4.15.0 and Fedora version 35.
What are the implications of CVE-2021-28710?
CVE-2021-28710 may lead to improper handling of address translations, potentially affecting system stability and security.
Is CVE-2021-28710 a widely known vulnerability?
Yes, CVE-2021-28710 is documented and recognized within the cybersecurity community, prompting updates and advisories from affected software projects.