csirt@kutim:~/threat-intel/cve/CVE-2021-28703

Katalog CVE

CVSS 7.0 · High EPSS 0,33%

Kerentanan pada xen. Skor CVSS 3.1 7.0 (High) menurut NVD.

Deskripsi (NVD)

grant table v2 status pages may remain accessible after de-allocation (take two) Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes. This bug was fortuitously fixed by code cleanup in Xen 4.14, and backported to security-supported Xen branches as a prerequisite of the fix for XSA-378.

Rincian

Terbit di NVD
7 Desember 2021
Terakhir diubah
17 Juni 2026
Status NVD
Modified
CVSS 3.1
7.0 (High), sumber NVD
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H · uraikan di kalkulator
EPSS (30 hari)
0,33% peluang dieksploitasi; lebih tinggi dari 24,4% CVE lain

Produk dan versi terdampak

VendorProdukVersi terdampak
xen xen Semua versi sebelum 14.4

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

Sumber: NVD · CVE.org · EPSS. Halaman ini disusun otomatis dari data tersebut; pembaruan terakhir 5 Okt 2026, 20:10 WITA. Kalau sistem di Perangkat Daerah memakai produk ini dan butuh bantuan, laporkan lewat kanal pelaporan.