SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2023-46842

When this is found not to be the case, it triggers a consistency check in the hypervisor and causes a crash.

MEDIUM 6.5EPSS 8.53%

Does this matter?

Lower severity and a low EPSS score (8.53%). Track it; it rarely justifies an emergency change on its own.

Description

Unlike 32-bit PV guests, HVM guests may switch freely between 64-bit and other modes. This in particular means that they may set registers used to pass 32-bit-mode hypercall arguments to values outside of the range 32-bit code would be able to set them to. When processing of hypercalls takes a considerable amount of time, the hypervisor may choose to invoke a hypercall continuation. Doing so involves putting (perhaps updated) hypercall arguments in respective registers. For guests not running in 64-bit mode this further involves a certain amount of translation of the values. Unfortunately internal sanity checking of these translated values assumes high halves of registers to always be clear when invoking a hypercall. When this is found not to be the case, it triggers a consistency check in the hypervisor and causes a crash.

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
EPSS
8.53% probability · 95th percentile
CISA KEV
Not listed
Weakness
CWE-843
Affected
xen/xen · fedoraproject/fedora
Source
security@xen.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.