Vulnerability in Xen
CVE-2022-26364
x86 pv: Insufficient care with non-coherent mappings T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] 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, Xen's safety logic doesn't account for CPU-induced cache non-coherency; cases where the CPU can cause the content of the cache to be different to the content in main memory. In such cases, Xen's safety logic can incorrectly conclude that the contents of a page is safe.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.7 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (40.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 40.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000
Affected products
- Xen — versions consult Xen advisory XSA-402
- Debian Linux — versions 11.0
- Fedoraproject Fedora — versions 35, 36
Public proof-of-concept exploits
References
- xenbits.xenproject.org/xsa/advisory-402.txt (Vendor Advisory)
- xenbits.xen.org/xsa/advisory-402.html (Patch, Vendor Advisory)
- www.openwall.com/lists/oss-security/2022/06/09/4 (mailing-list, Mailing List, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- packetstormsecurity.com/files/167710/Xen-PV-Guest-Non-SELFSNOOP-CPU-Memory-Corr… (Exploit, VDB Entry, Third Party Advisory)
- www.debian.org/security/2022/dsa-5184 (vendor-advisory, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- security.gentoo.org/glsa/202208-23 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2022-26364?
- CVE-2022-26364 is a medium-severity vulnerability in Xen. CVSS score: 6.7/10. Published 2022-06-09.
- How severe is CVE-2022-26364?
- Medium severity. CVSS v3 base score is 6.7 out of 10.
- Is CVE-2022-26364 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.