CVE-2017-12855

描述

Xen maintains the _GTF_{read,writ}ing bits as appropriate, to inform the guest that a grant is in use. A guest is expected not to modify the grant details while it is in use, whereas the guest is free to modify/reuse the grant entry when it is not in use. Under some circumstances, Xen will clear the status bits too early, incorrectly informing the guest that the grant is no longer in use. A guest may prematurely believe that a granted frame is safely private again, and reuse it in a way which contains sensitive information, while the domain on the far end of the grant is still using the grant. Xen 4.9, 4.8, 4.7, 4.6, and 4.5 are affected.

如何修補 CVE-2017-12855

要修補 CVE-2017-12855,請將受影響套件升級到下列已修補版本。

• —升級至 4.9.0-r1 或更新版本
• —升級至 4.8.1-1+deb9u3 或更新版本

CVE-2017-12855 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, < 4.9.0-r1
• from 0, < 4.8.1-1+deb9u3

CVSS 分數

參考連結(2)

• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2017-12855
• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2017-12855