Vulnerability in Xen
CVE-2022-26362
x86 pv: Race condition in typeref acquisition Xen maintains a type reference count for pages, in addition to a regular reference count. This scheme is used to maintain invariants required for Xen's safety, e.g. PV guests may not have direct writeable access to pagetables; updates need auditing by Xen. Unfortunately, the logic for acquiring a type reference has a race condition, whereby a safely TLB flush is issued too early and creates a window where the guest can re-establish the read/write mapping before writeability is prohibited.
Vulnerability class: Race Condition
EPSS: 0.004 (30.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Xen — versions consult Xen advisory XSA-401
- Debian Debian_linux — versions 11.0
- Fedoraproject Fedora — versions 35, 36
Weakness classification (CWE)
References
- security@xen.org (x_refsource_MISC, Vendor Advisory)
- security@xen.org (x_refsource_CONFIRM, Patch, Vendor Advisory)
- security@xen.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- security@xen.org (x_refsource_FEDORA, vendor-advisory)
- security@xen.org (VDB Entry, Third Party Advisory, x_refsource_MISC)
- security@xen.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
- security@xen.org (x_refsource_FEDORA, vendor-advisory)
- security@xen.org (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
Frequently asked questions
- What is CVE-2022-26362?
- CVE-2022-26362 is a medium-severity vulnerability in Xen, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 6.4/10. Published 2022-06-09.
- How severe is CVE-2022-26362?
- Medium severity. CVSS v3 base score is 6.4 out of 10.