CVE-2021-28710

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.

• CWE-269

• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT/
• https://security.gentoo.org/glsa/202208-23Third Party Advisory
• https://xenbits.xenproject.org/xsa/advisory-390.txtVendor Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT/
• https://security.gentoo.org/glsa/202208-23Third Party Advisory
• https://xenbits.xenproject.org/xsa/advisory-390.txtVendor Advisory

Published

Nov 21, 2021

Last Modified

Jun 17, 2026

Status

Modified

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• CVE-2021-28705issues with partially successful P2M updates on x86 T[his CN…7.8
• CVE-2021-28706guests may exceed their designated memory limit When a guest…8.6
• CVE-2021-28707PoD operations on misaligned GFNs T[his CNA information reco…8.8
• CVE-2021-28708PoD operations on misaligned GFNs T[his CNA information reco…8.8
• CVE-2021-28709issues with partially successful P2M updates on x86 T[his CN…7.8
• CVE-2021-28711Rogue backends can cause DoS of guests via high frequency ev…6.5
• CVE-2021-28712Rogue backends can cause DoS of guests via high frequency ev…6.5
• CVE-2021-28713Rogue backends can cause DoS of guests via high frequency ev…6.5
• CVE-2021-28714Guest can force Linux netback driver to hog large amounts of…6.5
• CVE-2021-28715Guest can force Linux netback driver to hog large amounts of…6.5
• CVE-2021-28732Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultID…