CVE-2022-33745

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-07-26 · updated 2026-06-17

Description

insufficient TLB flush for x86 PV guests in shadow mode For migration as well as to work around kernels unaware of L1TF (see XSA-273), PV guests may be run in shadow paging mode. To address XSA-401, code was moved inside a function in Xen. This code movement missed a variable changing meaning / value between old and new code positions. The now wrong use of the variable did lead to a wrong TLB flush condition, omitting flushes where such are necessary.

Affected products

Debian Linux: 11.0
Fedoraproject Fedora: 35, 36
xen: all versions

References

http://www.openwall.com/lists/oss-security/2022/07/26/2
http://www.openwall.com/lists/oss-security/2022/07/26/3
http://xenbits.xen.org/xsa/advisory-408.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HUFIMNGYP5VQAA6KE3T2I5GW6UP6F7BS/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MYI3OMJ7RIZNL3C6GUWNANNPEUUID6FM/
https://www.debian.org/security/2022/dsa-5272
https://xenbits.xenproject.org/xsa/advisory-408.txt
http://www.openwall.com/lists/oss-security/2022/07/26/2
http://www.openwall.com/lists/oss-security/2022/07/26/3
http://xenbits.xen.org/xsa/advisory-408.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HUFIMNGYP5VQAA6KE3T2I5GW6UP6F7BS/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MYI3OMJ7RIZNL3C6GUWNANNPEUUID6FM/

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