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CVE-2020-15565

21
FAUCET Score

CVE-2020-15565 is a high-severity vulnerability in Xen through 4.13.x, specifically affecting x86 Intel HVM guest OS users. It stems from insufficient cache write-back under VT-d when page tables are shared between IOMMU and CPU, potentially allowing a malicious guest to retain read/write DMA access to Xen's free memory pool. This can lead to a host OS denial of service or privilege escalation. The vulnerability has a CVSS score of 8.8 (HIGH) due to its low attack complexity and significant impact on confidentiality, integrity, and availability. There is currently no known active exploitation, publicly available exploit code, or significant community discussion surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
>= 3.2.0, <= 4.13.1CPE matchmatch criteria
cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:*
10.0CPE matchmatch criteria
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
31CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
32CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
15.1CPE matchmatch criteria
cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

8.8HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
2.0
Impact Score
6.0
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.37%
Probability of exploitation in next 30 days
EPSS Percentile
29.3%
Percentile rank of EPSS score among Peer Group
As of 2026-07-28
Model: v2026.06.15
This CVE's current EPSS score of 0.0037 is in the 68th percentile among its peer group of 17,070 CVEs.

Social Chatter

No social media mentions found for this CVE.

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.2 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Vendor Advisories (1)

redhatCVE-2020-15565Moderate

xen: insufficient cache write-back under VT-d leads to DoS (XSA-321)

Jul 7, 2020

References

lists.opensuse.org / opensuse-security-announce/2020-07/msg00024.html
Mailing ListThird Party Advisory
lists.opensuse.org / opensuse-security-announce/2020-07/msg00031.html
Mailing ListThird Party Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/MXESCOVI7AVRNC7HEAMFM7PMEO6D3AUH
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/VB3QJJZV23Z2IDYEMIHELWYSQBUEW6JP
security.gentoo.org / glsa/202007-02
Third Party Advisory
debian.org / security/2020/dsa-4723
Third Party Advisory
openwall.com / lists/oss-security/2020/07/07/4
Mailing ListThird Party Advisory
xenbits.xen.org / xsa/advisory-321.html
PatchThird Party Advisory