CVE-2021-28701

描述

Another race in XENMAPSPACE_grant_table handling Guests are 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, are de-allocated when a guest switches (back) from v2 to v1. Freeing such pages requires that the hypervisor enforce that no parallel request can result in the addition of a mapping of such a page to a guest. That enforcement was missing, allowing guests to retain access to pages that were freed and perhaps re-used for other purposes. Unfortunately, when XSA-379 was being prepared, this similar issue was not noticed.

如何修補 CVE-2021-28701

要修補 CVE-2021-28701,請將受影響套件升級到下列已修補版本。

• —升級至 4.13.3-r3 或更新版本

CVE-2021-28701 正在被利用嗎?

低 — EPSS 為 0.3%,目前沒有觀察到大規模利用活動。

受影響套件(1)

• >= 4.0.0, < 4.13.3-r3

CVSS 分數

參考連結(1)

• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2021-28701