Severity by source
AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Lifecycle Timeline
3DescriptionCVE.org
In the context switch logic Xen attempts to skip an IBPB in the case of a vCPU returning to a CPU on which it was the previous vCPU to run. While safe for Xen's isolation between vCPUs, this prevents the guest kernel correctly isolating between tasks. Consider:
- vCPU runs on CPU A, running task 1.
- vCPU moves to CPU B, idle gets scheduled on A. Xen skips IBPB.
- On CPU B, guest kernel switches from task 1 to 2, issuing IBPB.
- vCPU moves back to CPU A. Xen skips IBPB again.
Now, task 2 is running on CPU A with task 1's training still in the BTB.
AnalysisAI
In the context switch logic Xen attempts to skip an IBPB in the case of a vCPU returning to a CPU on which it was the previous vCPU to run. While safe for Xen's isolation between vCPUs, this prevents the guest kernel correctly isolating between tasks. [CVSS 2.9 LOW]
Technical ContextAI
Affects Xen. In the context switch logic Xen attempts to skip an IBPB in the case of a vCPU returning to a CPU on which it was the previous vCPU to run. While safe for Xen's isolation between vCPUs, this prevents the guest kernel correctly isolating between tasks. Consider:
- vCPU runs on CPU A, running task 1.
- vCPU moves to CPU B, idle gets scheduled on A. Xen skips IBPB.
- On CPU B, guest kernel switches from task 1 to 2, issuing IBPB.
- vCPU moves back to CPU A. Xen skips IBPB again.
Now, t
RemediationAI
A vendor patch is available — apply it immediately.
Same weakness CWE-665 – Improper Initialization
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External POC / Exploit Code
Leaving vuln.today