CVSS: 7.8EPSS: 0%CPEs: 1EXPL: 0CVE-2023-34325 – Multiple vulnerabilities in libfsimage disk handling
https://notcve.org/view.php?id=CVE-2023-34325
[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. [Este registro de información de la CNA se relaciona con múltiples CVE; el texto explica qué aspectos/vulnerabilidades corresponden a cada CVE.] libfsimage contiene código de análisis para varios sistemas de archivos, la mayoría de ellos basados en código heredado de grub. • https://xenbits.xenproject.org/xsa/advisory-443.html • CWE-787: Out-of-bounds Write •
CVSS: 7.8EPSS: 0%CPEs: 1EXPL: 0CVE-2023-34326 – x86/AMD: missing IOMMU TLB flushing
https://notcve.org/view.php?id=CVE-2023-34326
The caching invalidation guidelines from the AMD-Vi specification (48882—Rev 3.07-PUB—Oct 2022) is incorrect on some hardware, as devices will malfunction (see stale DMA mappings) if some fields of the DTE are updated but the IOMMU TLB is not flushed. Such stale DMA mappings can point to memory ranges not owned by the guest, thus allowing access to unindented memory regions. Las pautas de invalidación de almacenamiento en caché de la especificación AMD-Vi (48882—Rev 3.07-PUB—octubre de 2022) son incorrectas en algunos hardware, ya que los dispositivos funcionarán mal (consulte las asignaciones de DMA obsoletas) si algunos campos del DTE se actualizan pero el IOMMU TLB no está eliminado. Estas asignaciones de DMA obsoletas pueden apuntar a rangos de memoria que no pertenecen al huésped, lo que permite el acceso a regiones de memoria sin sangría. • https://xenbits.xenproject.org/xsa/advisory-442.html •
CVSS: 5.5EPSS: 0%CPEs: 1EXPL: 0CVE-2023-34323 – xenstored: A transaction conflict can crash C Xenstored
https://notcve.org/view.php?id=CVE-2023-34323
When a transaction is committed, C Xenstored will first check the quota is correct before attempting to commit any nodes. It would be possible that accounting is temporarily negative if a node has been removed outside of the transaction. Unfortunately, some versions of C Xenstored are assuming that the quota cannot be negative and are using assert() to confirm it. This will lead to C Xenstored crash when tools are built without -DNDEBUG (this is the default). Cuando se confirma una transacción, C Xenstored primero verificará que la cuota sea correcta antes de intentar confirmar cualquier nodo. Sería posible que la contabilidad fuera temporalmente negativa si se hubiera eliminado un nodo fuera de la transacción. • https://xenbits.xenproject.org/xsa/advisory-440.html • CWE-476: NULL Pointer Dereference •
CVSS: 7.8EPSS: 0%CPEs: 1EXPL: 0CVE-2023-34322 – top-level shadow reference dropped too early for 64-bit PV guests
https://notcve.org/view.php?id=CVE-2023-34322
For migration as well as to work around kernels unaware of L1TF (see XSA-273), PV guests may be run in shadow paging mode. Since Xen itself needs to be mapped when PV guests run, Xen and shadowed PV guests run directly the respective shadow page tables. For 64-bit PV guests this means running on the shadow of the guest root page table. In the course of dealing with shortage of memory in the shadow pool associated with a domain, shadows of page tables may be torn down. This tearing down may include the shadow root page table that the CPU in question is presently running on. While a precaution exists to supposedly prevent the tearing down of the underlying live page table, the time window covered by that precaution isn't large enough. • https://xenbits.xenproject.org/xsa/advisory-438.html • CWE-273: Improper Check for Dropped Privileges •
CVSS: 3.3EPSS: 0%CPEs: 1EXPL: 0CVE-2023-34321 – arm32: The cache may not be properly cleaned/invalidated
https://notcve.org/view.php?id=CVE-2023-34321
Arm provides multiple helpers to clean & invalidate the cache for a given region. This is, for instance, used when allocating guest memory to ensure any writes (such as the ones during scrubbing) have reached memory before handing over the page to a guest. Unfortunately, the arithmetics in the helpers can overflow and would then result to skip the cache cleaning/invalidation. Therefore there is no guarantee when all the writes will reach the memory. Arm proporciona múltiples ayudas para limpiar e invalidar el caché de una región determinada. Esto se utiliza, por ejemplo, al asignar memoria de invitado para garantizar que cualquier escritura (como las que se realizan durante la depuración) haya llegado a la memoria antes de entregar la página a un invitado. • https://xenbits.xenproject.org/xsa/advisory-437.html • CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer •