SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2015-8555

Xen 4.6.x, 4.5.x, 4.4.x, 4.3.x, and earlier do not initialize x86 FPU stack and XMM registers when XSAVE/XRSTOR are not used to manage guest extended register state, which allows local guest domains to obtain sensitive information from other domains via…

HIGH 8.6EPSS 2.25%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (2.25%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Xen 4.6.x, 4.5.x, 4.4.x, 4.3.x, and earlier do not initialize x86 FPU stack and XMM registers when XSAVE/XRSTOR are not used to manage guest extended register state, which allows local guest domains to obtain sensitive information from other domains via unspecified vectors.

CVSS 3.0
8.6 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
EPSS
2.25% probability · 82th percentile
CISA KEV
Not listed
Weakness
CWE-200
Affected
citrix/xenserver · xen/xen
Source
cve@mitre.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.