4.9 Medium
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
NONE
Availability Impact
NONE
AV:L/AC:L/Au:N/C:C/I:N/A:N
6.5 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
0.001 Low
EPSS
Percentile
26.7%
The block interface response structure has some discontiguous fields. Certain backends populate the structure fields of an otherwise uninitialized instance of this structure on their stacks, leaking data through the (internal or trailing) padding field.
A malicious unprivileged guest may be able to obtain sensitive information from the host or other guests.
All Linux versions supporting the xen-blkback, blkback, or blktap drivers are vulnerable.
FreeBSD, NetBSD and Windows (with or without PV drivers) are not vulnerable (either because they do not have backends at all, or because they use a different implementation technique which does not suffer from this problem).
All qemu versions supporting the Xen block backend are vulnerable. The qemu-xen-traditional code base does not include such code, so is not vulnerable. Note that an instance of qemu will be spawned to provide the backend for most non-raw-format disks; so you may need to apply the patch to qemu even if you use only PV guests.
4.9 Medium
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
NONE
Availability Impact
NONE
AV:L/AC:L/Au:N/C:C/I:N/A:N
6.5 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
0.001 Low
EPSS
Percentile
26.7%