CVE-2021-27379
An issue was discovered in Xen through 4.11.x, allowing x86 Intel HVM guest OS users to achieve unintended read/write DMA access, and possibly cause a denial of service (host OS crash) or gain privileges.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.36%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
An issue was discovered in Xen through 4.11.x, allowing x86 Intel HVM guest OS users to achieve unintended read/write DMA access, and possibly cause a denial of service (host OS crash) or gain privileges. This occurs because a backport missed a flush, and thus IOMMU updates were not always correct. NOTE: this issue exists because of an incomplete fix for CVE-2020-15565.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.36% probability · 29th percentile
- CISA KEV
- Not listed
- Affected
- xen/xen · debian/debian linux
- Source
- cve@mitre.org
References
- http://www.openwall.com/lists/oss-security/2021/02/23/1Mailing List, Third Party Advisory
- http://xenbits.xen.org/xsa/advisory-366.htmlMitigation, Patch, Vendor Advisory
- https://www.debian.org/security/2021/dsa-4888Third Party Advisory
- https://xenbits.xen.org/xsa/advisory-366.htmlPatch, Vendor Advisory
- http://www.openwall.com/lists/oss-security/2021/02/23/1Mailing List, Third Party Advisory
- http://xenbits.xen.org/xsa/advisory-366.htmlMitigation, Patch, Vendor Advisory
- https://www.debian.org/security/2021/dsa-4888Third Party Advisory
- https://xenbits.xen.org/xsa/advisory-366.htmlPatch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.