Xen ProjectXSA-372xen/arm: Boot modules are not scrubbed
2.1 Low
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:L/AC:L/Au:N/C:P/I:N/A:N
5.5 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
0.0004 Low
EPSS
Percentile
12.6%
ISSUE DESCRIPTION
The bootloader will load boot modules (e.g. kernel, initramfs…) in a temporary area before they are copied by Xen to each domain memory. To ensure sensitive data is not leaked from the modules, Xen must “scrub” them before handing the page over to the allocator.
Unfortunately, it was discovered that modules will not be scrubbed on Arm.
IMPACT
Sensitive information from the boot modules might be visible to another domain after boot.
VULNERABLE SYSTEMS
Only Arm systems are vulnerable. System running with “bootscrub=off” (disabling boot scrubbing) are not vulnerable.
All versions of Xen since 4.12 are vulnerable.
Related
2.1 Low
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:L/AC:L/Au:N/C:P/I:N/A:N
5.5 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
0.0004 Low
EPSS
Percentile
12.6%