CVE-2016-9637

The (1) ioport_read and (2) ioport_write functions in Xen, when qemu is used as a device model within Xen, might allow local x86 HVM guest OS administrators to gain qemu process privileges via vectors involving an out-of-range ioport access.

Published: 2017-02-17 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-9637 is rated Low Risk (37.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.09%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2016-9637

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 2025-03-30 0.22% 0.09% -0.13%
2 2025-03-29 0.06% 0.22% +0.15%
3 2023-03-07 — 0.06% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-9637

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.0 HIGH
CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:C/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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
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.
 0.8 6.0 [email protected]
3.7 2.0 LOW
AV:L/AC:H/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:H)
Exploitation requires uncommon or highly specific conditions.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 1.9 6.4 [email protected]

Weakness enumeration for CVE-2016-9637

OS Trackers for CVE-2016-9637

vendor priority summary link
debian unimportant CVE-2016-9637 unimportant priority: Debian including 2 source packages (qemu, xen), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 10. https://security-tracker.debian.org/tracker/CVE-2016-9637
gentoo normal CVE-2016-9637: 1 GLSA(s) (201612-56), 3 atom(s) (app-emulation/xen, app-emulation/xen-pvgrub, app-emulation/xen-tools); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-9637
redhat high — https://access.redhat.com/security/cve/CVE-2016-9637
suse medium CVE-2016-9637 severity moderate: SUSE including 378 source package names (amazon/suse-sles-15-sp1-chost-byos-v20210304-hvm-ssd-x86_64, amazon/suse-sles-15-sp1-chost-byos-v20220127-hvm-ssd-x86_64, …), 498 product×package rows across 65 product lines (HPE Helion OpenStack 8, SUSE Linux Enterprise Desktop 12 SP1, … (65 product lines)): Fixed 298, Known Affected 157, Known Not Affected 43. https://www.suse.com/security/cve/CVE-2016-9637/
ubuntu medium CVE-2016-9637 medium priority: Ubuntu including 3 source packages (qemu, qemu-kvm, xen), 15 status rows across 5 suites (precise, trusty, upstream, xenial, yakkety): not-affected 6, DNE 4, needs-triage 3, released 2. https://ubuntu.com/security/CVE-2016-9637

Affected software / configurations for CVE-2016-9637

Vendor Product Version Raw CPE
citrix xenserver 6.0.2 cpe:2.3:a:citrix:xenserver:6.0.2:*:*:*:*:*:*:*
citrix xenserver 6.2.0 cpe:2.3:a:citrix:xenserver:6.2.0:sp1:*:*:*:*:*:*
citrix xenserver 6.5 cpe:2.3:a:citrix:xenserver:6.5:sp1:*:*:*:*:*:*
citrix xenserver 7.0 cpe:2.3:a:citrix:xenserver:7.0:*:*:*:*:*:*:*

References for CVE-2016-9637

cvelogic Threat Intelligence