{"id":"DEBIAN-CVE-2023-46836","details":"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.","modified":"2026-09-15T09:02:46.478061238Z","published":"2024-01-05T17:15:11.197Z","upstream":["CVE-2023-46836"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2023-46836"}],"affected":[{"package":{"name":"xen","ecosystem":"Debian:12","purl":"pkg:deb/debian/xen?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.17.2+76-ge1f9cb16e2-1~deb12u1"}]}],"versions":["4.17.1+2-gb773c48e36-1","4.17.2+55-g0b56bed864-1","4.17.2-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-46836.json"}},{"package":{"name":"xen","ecosystem":"Debian:13","purl":"pkg:deb/debian/xen?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.17.2+76-ge1f9cb16e2-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-46836.json"}},{"package":{"name":"xen","ecosystem":"Debian:14","purl":"pkg:deb/debian/xen?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.17.2+76-ge1f9cb16e2-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-46836.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N"}]}