CVE-2020-25596

描述

An issue was discovered in Xen through 4.14.x. x86 PV guest kernels can experience denial of service via SYSENTER. The SYSENTER instruction leaves various state sanitization activities to software. One of Xen's sanitization paths injects a #GP fault, and incorrectly delivers it twice to the guest. This causes the guest kernel to observe a kernel-privilege #GP fault (typically fatal) rather than a user-privilege #GP fault (usually converted into SIGSEGV/etc.). Malicious or buggy userspace can crash the guest kernel, resulting in a VM Denial of Service. All versions of Xen from 3.2 onwards are vulnerable. Only x86 systems are vulnerable. ARM platforms are not vulnerable. Only x86 systems that support the SYSENTER instruction in 64bit mode are vulnerable. This is believed to be Intel, Centaur, and Shanghai CPUs. AMD and Hygon CPUs are not believed to be vulnerable. Only x86 PV guests can exploit the vulnerability. x86 PVH / HVM guests cannot exploit the vulnerability.

如何修補 CVE-2020-25596

要修補 CVE-2020-25596,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

CVE-2020-25596 正在被利用嗎?

低 — EPSS 為 0.5%,目前沒有觀察到大規模利用活動。

受影響套件(1)

• >= 3.2.0, < 4.12.3-r4

CVSS 分數

參考連結(1)

• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2020-25596