CVE-2023-34325 Multiple vulnerabilities in libfsimage disk handling
A stack buffer overflow in Xen's libfsimage allows guest-controlled input to trigger memory corruption, potentially leading to code execution with root privileges.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-34325?
CVE-2023-34325 is a high-severity memory corruption vulnerability in Xen Xen, published on 5 Jan 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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 drive) can present a modified XFS partition to grub-legacy in such a way to exploit a memory corruption in grub’s XFS file system implementation.") CVE-2023-34325 refers specifically to the vulnerabilities in Xen's copy of libfsimage, which is decended from a very old version of grub.
Weakness: CWE-787
Which versions are affected by CVE-2023-34325?
It affects 1 product.
Products include Xen Xen.
How do I fix CVE-2023-34325?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2023-34325 being exploited?
There is no known exploitation of CVE-2023-34325 in the wild and no public exploit code.
Other vulnerabilities in Xen Xen
Sources
Also known as ALPINE-CVE-2023-34325, DEBIAN-CVE-2023-34325, GHSA-gwmw-qvr5-88j2, UBUNTU-CVE-2023-34325.