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PatchSiren cyber security CVE debrief

CVE-2016-10024 Citrix CVE debrief

CVE-2016-10024 is a local denial-of-service flaw in Xen and related Citrix XenServer builds. A privileged x86 paravirtualized guest kernel administrator can asynchronously modify the instruction stream during certain kernel operations, which can hang or crash the host.

Vendor
Citrix
Product
Xenserver
CVSS
MEDIUM 6
CISA KEV
Not listed in stored evidence
Original CVE published
2017-01-26
Original CVE updated
2026-05-13
Advisory published
2017-01-26
Advisory updated
2026-05-13

Who should care

Operators running Xen 4.8.x or affected Citrix XenServer releases, especially in environments that allow privileged paravirtualized guest administration.

Technical summary

NVD describes an availability issue in Xen through 4.8.0. On x86 PV guests, a guest kernel administrator can alter the instruction stream asynchronously while certain kernel operations are in progress, leading to host hang or crash. The NVD record maps the weakness to CWE-20 and lists affected Citrix XenServer releases 6.0.2, 6.2.0, 6.5, and 7.0.

Defensive priority

Medium — prioritize patching on any affected Xen or XenServer host because the impact is host-level availability loss, but exploitation requires local high-privilege guest access.

Recommended defensive actions

  • Apply the vendor fix referenced by Xen Security Advisory XSA-202 and the Citrix CTX219378 advisory across affected hosts.
  • Upgrade or replace Xen 4.8.x and the affected Citrix XenServer releases identified in the NVD CPE criteria.
  • Restrict who can administer guest kernels on x86 PV guests; treat guest kernel administrators as highly trusted.
  • Verify patch status across all hypervisor nodes and plan maintenance windows to safely restart or recycle hosts if needed.

Evidence notes

The supplied NVD record states that Xen through 4.8.0 is affected and that local x86 PV guest OS kernel administrators can cause a host hang or crash by modifying the instruction stream asynchronously during certain kernel operations. The same record lists affected Citrix XenServer versions and includes references to Xen advisory XSA-202, Citrix CTX219378, Debian DSA-3847, and Gentoo GLSA-201612-56. NVD also classifies the weakness as CWE-20.

Sources and references

Verified primary and authoritative sources

  • CVE-2016-10024 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2016-10024

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2016-10024 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2016-10024

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.