Vulnerability Description
IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Both AMD and Intel allow ACPI tables to specify regions of memory which should be left untranslated, which typically means these addresses should pass the translation phase unaltered. While these are typically device specific ACPI properties, they can also be specified to apply to a range of devices, or even all devices. On all systems with such regions Xen failed to prevent guests from undoing/replacing such mappings (CVE-2021-28694). On AMD systems, where a discontinuous range is specified by firmware, the supposedly-excluded middle range will also be identity-mapped (CVE-2021-28695). Further, on AMD systems, upon de-assigment of a physical device from a guest, the identity mappings would be left in place, allowing a guest continued access to ranges of memory which it shouldn't have access to anymore (CVE-2021-28696).
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Xen | Xen | All versions |
| Fedoraproject | Fedora | 33 |
| Debian | Debian Linux | 11.0 |
Related Weaknesses (CWE)
References
- http://www.openwall.com/lists/oss-security/2021/09/01/1Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/09/01/5Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/09/01/6Mailing ListThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202208-23Third Party Advisory
- https://www.debian.org/security/2021/dsa-4977Third Party Advisory
- https://xenbits.xenproject.org/xsa/advisory-378.txtVendor Advisory
- http://www.openwall.com/lists/oss-security/2021/09/01/1Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/09/01/5Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/09/01/6Mailing ListThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
FAQ
What is CVE-2021-28696?
CVE-2021-28696 is a vulnerability with a CVSS score of 6.8 (MEDIUM). IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Both AMD and Intel allow ACPI tables t...
How severe is CVE-2021-28696?
CVE-2021-28696 has been rated MEDIUM with a CVSS base score of 6.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-28696?
Check the references section above for vendor advisories and patch information. Affected products include: Xen Xen, Fedoraproject Fedora, Debian Debian Linux.