CVE-2016-4480

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.

Published: 2016-05-18 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-4480 is rated Moderate Risk (48.2/100): CVSS High severity, with low exploitation likelihood (EPSS 0.55%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2016-4480

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.40% 0.55% +0.14%
2 2026-02-18 0.52% 0.40% -0.11%
3 2025-12-03 — 0.52% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-4480

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.4 3.0 HIGH
CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.5 5.9 [email protected]
7.2 2.0 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 3.9 10.0 [email protected]

Weakness enumeration for CVE-2016-4480

OS Trackers for CVE-2016-4480

vendor priority summary link
debian not yet assigned CVE-2016-4480 not yet assigned priority: Debian including 1 source packages (xen), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2016-4480
redhat medium — https://access.redhat.com/security/cve/CVE-2016-4480
ubuntu low CVE-2016-4480 low priority: Ubuntu including 24 source packages (linux, linux-armadaxp, …), 120 status rows across 5 suites (precise, trusty, upstream, wily, xenial): DNE 70, not-affected 38, ignored 7, released 4, needs-triage 1. https://ubuntu.com/security/CVE-2016-4480

Affected software / configurations for CVE-2016-4480

Vendor Product Version Raw CPE
oracle vm_server 3.2 cpe:2.3:o:oracle:vm_server:3.2:*:*:*:*:*:*:*
oracle vm_server 3.3 cpe:2.3:o:oracle:vm_server:3.3:*:*:*:*:*:*:*
oracle vm_server 3.4 cpe:2.3:o:oracle:vm_server:3.4:*:*:*:*:*:*:*
xen xen <= 4.6.1 cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*

References for CVE-2016-4480

cvelogic Threat Intelligence