CVE-2019-18420
描述
An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to cause a denial of service via a VCPUOP_initialise hypercall. hypercall_create_continuation() is a variadic function which uses a printf-like format string to interpret its parameters. Error handling for a bad format character was done using BUG(), which crashes Xen. One path, via the VCPUOP_initialise hypercall, has a bad format character. The BUG() can be hit if VCPUOP_initialise executes for a sufficiently long period of time for a continuation to be created. Malicious guests may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen versions 4.6 and newer are vulnerable. Xen versions 4.5 and earlier are not vulnerable. Only x86 PV guests can exploit the vulnerability. HVM and PVH guests, and guests on ARM systems, cannot exploit the vulnerability.
如何修補 CVE-2019-18420
要修補 CVE-2019-18420,請將受影響套件升級到下列已修補版本。
- —升級至 4.11.2-r0 或更新版本
- —升級至 4.11.3+24-g14b62ab3e5-1 或更新版本
CVE-2019-18420 正在被利用嗎?
低 — EPSS 為 2.5%,目前沒有觀察到大規模利用活動。
受影響套件(2)
- from 0, < 4.11.2-r0
- from 0, < 4.11.3+24-g14b62ab3e5-1
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |