Vulnerability in Xen
CVE-2022-33745
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.003 (20.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 20.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Xen — versions consult Xen advisory XSA-408
- Debian Linux — versions 11.0
- Fedoraproject Fedora — versions 35, 36
References
- xenbits.xenproject.org/xsa/advisory-408.txt (Vendor Advisory)
- xenbits.xen.org/xsa/advisory-408.html (Patch, Vendor Advisory)
- www.openwall.com/lists/oss-security/2022/07/26/2 (mailing-list, Patch, Mailing List, Third Party Advisory)
- www.openwall.com/lists/oss-security/2022/07/26/3 (mailing-list, Patch, Mailing List, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- www.debian.org/security/2022/dsa-5272 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2022-33745?
- CVE-2022-33745 is a high-severity vulnerability in Xen. CVSS score: 8.8/10. Published 2022-07-26.
- How severe is CVE-2022-33745?
- High severity. CVSS v3 base score is 8.8 out of 10.