xen: x86 software guest page walk PS bit handling flaw (XSA-176)
Published May 18, 2016
8.4
HIGHCVSS 3.0
EPSS 0.54%
Description
The guest_walk_tables function in arch/x86/mm/guest_walk.c in Xen 4.6.x and earlier does not properly handle the Page Size (PS) page table entry bit at the L4 and L3 page table levels, which might allow local guest OS users to gain privileges via a crafted mapping of memory.
Affected products
No data.
No data.
Red Hat Enterprise Linux 5
xen
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | xen | Not affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
AV:L/AC:L/Au:N/C:C/I:C/A:C
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (11 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.54% (0.00542) | 43.51th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.55% (0.00547) | 41.29th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.09% (0.00090) | 23.52th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.92% (0.00915) | 83.54th | v3 (v2023.03.01) |
| Jul 16, 2024 | 0.47% (0.00466) | 75.73th | v3 (v2023.03.01) |
| Mar 10, 2024 | 0.15% (0.00155) | 50.86th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.13% (0.00134) | 46.73th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.02% (0.01018) | 40.69th | v2 (v2022.01.01) |
| Sep 10, 2022 | 1.02% (0.01018) | 38.88th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.02% (0.01018) | 36.86th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.02% (0.01018) | 19.50th | v2 (v2022.01.01) |
References (9)
- http://www.debian.org/security/2016/dsa-3633 vendor-advisoryx_refsource_DEBIAN
- http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html x_refsource_CONFIRMVendor Advisory
- http://www.securityfocus.com/bid/90710 vdb-entryx_refsource_BID
- http://www.securitytracker.com/id/1035901 vdb-entryx_refsource_SECTRACK
- http://xenbits.xen.org/xsa/advisory-176.html x_refsource_CONFIRMVendor Advisory
- https://access.redhat.com/security/cve/CVE-2016-4480 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1332657 Issue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2016-4480
- https://www.cve.org/CVERecord?id=CVE-2016-4480
| Link | Providers | Tags |
|---|---|---|
| http://www.debian.org/security/2016/dsa-3633 | vendor-advisoryx_refsource_DEBIAN | |
| http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html | x_refsource_CONFIRMVendor Advisory | |
| http://www.securityfocus.com/bid/90710 | vdb-entryx_refsource_BID | |
| http://www.securitytracker.com/id/1035901 | vdb-entryx_refsource_SECTRACK | |
| http://xenbits.xen.org/xsa/advisory-176.html | x_refsource_CONFIRMVendor Advisory | |
| https://access.redhat.com/security/cve/CVE-2016-4480 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1332657 | Issue Tracking | |
| https://nvd.nist.gov/vuln/detail/CVE-2016-4480 | ||
| https://www.cve.org/CVERecord?id=CVE-2016-4480 |
Change history (0)
No recorded changes yet.