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Debian LinuxOperating system · Debian

CVE-2019-17340

HIGH · 8.8 CVSS v3.1 Published 2019-10-08
Fix available
A fix is available. Upgrade to after 4.11.2 or later.
See remediation →
90/100
Remediation priority · Urgent
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An issue was discovered in Xen through 4.11.x allowing x86 guest OS users to cause a denial of service or gain privileges because grant-table transfer requests are mishandled.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A vulnerability in Xen's grant-table mechanism allows x86 guest OS users to cause denial of service or gain privileges by exploiting mishandled grant-table transfer requests. The grant table is a Xen feature enabling memory sharing between guests and the hypervisor; improper handling of transfer requests can allow a malicious guest to escape its isolation boundary and potentially escalate privileges or crash the host.

MitigationUpgrade Xen to a version beyond 4.11.x that includes the patch for this vulnerability. Given the CVSS 8.8 severity and potential for guest-to-host privilege escalation, prioritize patching in production environments promptly.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Debian LinuxOperating system
Affected:= 9.0= 10.0
XenOperating system
Affected:>= 3.2.0, <= 4.11.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify if Xen hypervisor is running
    Run 'xl list' or 'xm list' on the host to list running domains. If Xen is active, you will see domain listings (including Domain-0). Alternatively, check the hypervisor with 'cat /proc/xen/xsd_port' (if Xen is running, this file exists).
    Affected if The system is not running Xen as the hypervisor (not affected).
  2. Determine the installed Xen version
    Run 'xl version' or 'xm version' to display the Xen hypervisor version. On Debian, you can also run 'dpkg -l | grep xen' to list installed Xen packages and their versions.
    Affected if The Xen version is between 3.2.0 and 4.11.2 inclusive (including 3.2.0 and 4.11.2). Versions below 3.2.0 or above 4.11.2 are not affected.
  3. Check if grant-table feature is in use
    Examine guest configuration files in /etc/xen/ (or /etc/libvirt/libxl/ for libxl-based setups) for the presence of 'grant_table' or 'grant_tables' settings. Run 'xl cfglist <guestname>' on a running guest to view its configuration and look for grant-table related parameters.
    Affected if Grant tables are enabled for any guest (this feature is often enabled by default for guests requiring shared memory access with the host).
  4. Identify if x86 guest domains are running
    Run 'xl list' and check the 'Arch' or 'OS' column for x86-based guests (i686, i386, x86_64, or amd64 architectures). Also check 'xl info' for the host architecture.
    Affected if x86 architecture guests are running on the affected Xen version (the vulnerability specifically affects x86 guest OS users).

Your environment is affected if you are running Xen versions 3.2.0 through 4.11.2 as your hypervisor, with grant-table functionality enabled, and x86 guest domains are active on the system.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 4.11.2
Interim mitigation

Upgrade Xen to a version beyond 4.11.x that includes the patch for this vulnerability. Given the CVSS 8.8 severity and potential for guest-to-host privilege escalation, prioritize patching in production environments promptly.

Fix this in Debian Linux Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-17340 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data