An issue was discovered in Xen through 4.11.x on AMD x86 platforms, possibly allowing guest OS users to gain host OS privileges because TLB flushes do not always occur after IOMMU mapping changes.
Weakness
The product does not properly “clean up” and remove temporary or supporting resources after they have been used.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Xen | Xen | * | 4.11.1 (including) |
| Xen | Ubuntu | bionic | * |
| Xen | Ubuntu | cosmic | * |
| Xen | Ubuntu | disco | * |
| Xen | Ubuntu | eoan | * |
| Xen | Ubuntu | esm-infra/bionic | * |
| Xen | Ubuntu | groovy | * |
| Xen | Ubuntu | hirsute | * |
| Xen | Ubuntu | impish | * |
| Xen | Ubuntu | trusty | * |
| Xen | Ubuntu | upstream | * |
| Xen | Ubuntu | xenial | * |
Potential Mitigations
References
- http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00072.html
- http://www.securityfocus.com/bid/106182
- https://lists.debian.org/debian-lts-announce/2019/10/msg00008.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UXC6BME7SXJI2ZIATNXCAH7RGPI4UKTT/
- https://support.citrix.com/article/CTX239432
- https://www.debian.org/security/2019/dsa-4369
- https://xenbits.xen.org/xsa/advisory-275.html
- http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00072.html
- http://www.securityfocus.com/bid/106182
- https://lists.debian.org/debian-lts-announce/2019/10/msg00008.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UXC6BME7SXJI2ZIATNXCAH7RGPI4UKTT/
- https://support.citrix.com/article/CTX239432
- https://www.debian.org/security/2019/dsa-4369
- https://xenbits.xen.org/xsa/advisory-275.html