CVE-2020-25601

描述

An issue was discovered in Xen through 4.14.x. There is a lack of preemption in evtchn_reset() / evtchn_destroy(). In particular, the FIFO event channel model allows guests to have a large number of event channels active at a time. Closing all of these (when resetting all event channels or when cleaning up after the guest) may take extended periods of time. So far, there was no arrangement for preemption at suitable intervals, allowing a CPU to spend an almost unbounded amount of time in the processing of these operations. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. All Xen versions are vulnerable in principle. Whether versions 4.3 and older are vulnerable depends on underlying hardware characteristics.

如何修補 CVE-2020-25601

要修補 CVE-2020-25601,請將受影響套件升級到下列已修補版本。

• —升級至 4.12.3-r4 或更新版本
• —升級至 4.14.0+80-gd101b417b7-1 或更新版本

CVE-2020-25601 正在被利用嗎?

低 — EPSS 為 0.4%,目前沒有觀察到大規模利用活動。

受影響套件(2)

• from 0, < 4.12.3-r4
• from 0, < 4.14.0+80-gd101b417b7-1

CVSS 分數

參考連結(2)

• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2020-25601
• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2020-25601