CVE-2023-34325

Technical Description

[This CNA information record relates to multiple CVEs; the

text explains which aspects/vulnerabilities correspond to which CVE.]

libfsimage contains parsing code for several filesystems, most of them based on

grub-legacy code. libfsimage is used by pygrub to inspect guest disks.

Pygrub runs as the same user as the toolstack (root in a priviledged domain).

At least one issue has been reported to the Xen Security Team that allows an

attacker to trigger a stack buffer overflow in libfsimage. After further

analisys the Xen Security Team is no longer confident in the suitability of

libfsimage when run against guest controlled input with super user priviledges.

In order to not affect current deployments that rely on pygrub patches are

provided in the resolution section of the advisory that allow running pygrub in

deprivileged mode.

CVE-2023-4949 refers to the original issue in the upstream grub

project ("An attacker with local access to a system (either through a

disk or external dri

Remediation

Check the references section for vendor advisories and patches from xen. Update xen to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References