Описание
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.
| Релиз | Статус | Примечание |
|---|---|---|
| bionic | ignored | end of standard support |
| devel | needs-triage | |
| esm-apps/focal | needs-triage | |
| esm-apps/jammy | needs-triage | |
| esm-apps/noble | needs-triage | |
| esm-infra/bionic | needs-triage | |
| esm-infra/xenial | needs-triage | |
| focal | ignored | end of standard support, was needs-triage |
| jammy | needs-triage | |
| lunar | ignored | end of life, was needs-triage |
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EPSS
4.7 Medium
CVSS3
Связанные уязвимости
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.
The fixes for XSA-422 (Branch Type Confusion) and XSA-434 (Speculative ...
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.
Уязвимость компонента IRQ Handler гипервизора Xen, позволяющая нарушителю раскрыть защищаемую информацию
EPSS
4.7 Medium
CVSS3