CVE-2021-26933

published 2021-02-17

CVE-2021-26933: An issue was discovered in Xen 4.9 through 4.14.x. On Arm, a guest is allowed to control whether memory accesses are bypassing the cache. This means that Xen…

Priority P4 23 medium 5.5 CVSS 3.1

AV L AC L PR L UI N S U C H I N A N

An issue was discovered in Xen 4.9 through 4.14.x. On Arm, a guest is allowed to control whether memory accesses are bypassing the cache. This means that Xen needs to ensure that all writes (such as the ones during scrubbing) have reached the memory before handing over the page to a guest. Unfortunately, the operation to clean the cache is happening before checking if the page was scrubbed. Therefore there is no guarantee when all the writes will reach the memory.

Affected

9 ranges

Vendor	Product	Version range	Fixed in
debian	debian_linux	—	—
debian	xen	< xen 4.14.1+11-gb0b734a8b3-1 (bookworm)	xen 4.14.1+11-gb0b734a8b3-1 (bookworm)
fedoraproject	fedora	—	—
fedoraproject	fedora	—	—
xen	xen	>= 0 < 4.14.1+11-gb0b734a8b3-1	4.14.1+11-gb0b734a8b3-1
xen	xen	>= 0 < 4.14.1+11-gb0b734a8b3-1	4.14.1+11-gb0b734a8b3-1
xen	xen	>= 0 < 4.14.1+11-gb0b734a8b3-1	4.14.1+11-gb0b734a8b3-1
xen	xen	>= 0 < 4.14.1+11-gb0b734a8b3-1	4.14.1+11-gb0b734a8b3-1
xen	xen	4.9.0 – 4.14.1	—

CVSS provenance

nvd v3.1 5.5 MEDIUM CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

nvd v2.0 2.1 LOW AV:L/AC:L/Au:N/C:P/I:N/A:N

osv 5.5 MEDIUM

vendor_debian 5.5 MEDIUM

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