Return Stack Overflow) are not IRQ-safe. It was believed that the
mitigations always operated in contexts with IRQs disabled.
However, the original XSA-254 fix for Meltdown (XPTI) deliberately left
interrupts enabled on two entry paths; one unconditionally, and one
conditionally on whether XPTI was active.
As BTC/SRSO and Meltdown affect different CPU vendors, the mitigations
are not active together by default. Therefore, there is a race
condition whereby a malicious PV guest can bypass BTC/SRSO protections
and launch a BTC/SRSO attack against Xen.
Analysis and contextual insights are available on OpenCVE Cloud.
Vendor Workaround
Running only HVM or PVH VMs will avoid the vulnerability.
Tracking
Sign in to view the affected projects.
| Source | ID | Title |
|---|---|---|
EUVD |
EUVD-2023-51002 | The fixes for XSA-422 (Branch Type Confusion) and XSA-434 (Speculative Return Stack Overflow) are not IRQ-safe. It was believed that the mitigations always operated in contexts with IRQs disabled. However, the original XSA-254 fix for Meltdown (XPTI) deliberately left interrupts enabled on two entry paths; one unconditionally, and one conditionally on whether XPTI was active. As BTC/SRSO and Meltdown affect different CPU vendors, the mitigations are not active together by default. Therefore, there is a race condition whereby a malicious PV guest can bypass BTC/SRSO protections and launch a BTC/SRSO attack against Xen. |
Tue, 04 Nov 2025 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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Tue, 03 Jun 2025 15:15:00 +0000
| Type | Values Removed | Values Added |
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| Metrics |
ssvc
|
Status: PUBLISHED
Assigner: XEN
Published:
Updated: 2025-11-04T19:25:42.692Z
Reserved: 2023-10-27T07:55:35.332Z
Link: CVE-2023-46836
Updated: 2025-11-04T19:25:42.692Z
Status : Modified
Published: 2024-01-05T17:15:11.197
Modified: 2025-11-04T20:17:10.557
Link: CVE-2023-46836
No data.
OpenCVE Enrichment
No data.
EUVD