dbcve.org
XenserverApplication · Citrix

CVE-2017-2620

CRITICAL · 9.9 CVSS v3.0 Published 2018-07-27
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable Zero-click Patch available

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
Quick emulator (QEMU) before 2.8 built with the Cirrus CLGD 54xx VGA Emulator support is vulnerable to an out-of-bounds access issue. The issue could occur while copying VGA data in cirrus_bitblt_cputovideo. A privileged user inside guest could use this flaw to crash the QEMU process OR potentially execute arbitrary code on host with privileges of the QEMU process.

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
How this class of weakness works · CWE-787

The program writes past the bounds of a buffer, overwriting adjacent memory an attacker can turn to their advantage. Crafted input can overwrite control data and redirect execution. Remediation is validating every index and length before a write, plus modern memory-safety mitigations.

General guidance for the out-of-bounds write class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

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
XenserverApplication
Affected:= 6.0.2= 6.2.0= 6.5= 7.0= 7.1
OpenstackApplication
Affected:= 5.0= 6.0= 7.0= 8= 9= 10
Debian LinuxOperating system
Affected:= 7.0
Enterprise Linux DesktopOperating system
Affected:= 6.0= 7.0
Enterprise Linux ServerOperating system
Affected:= 6.0= 7.0
Enterprise Linux Server AusOperating system
Affected:= 7.3= 7.4
Enterprise Linux Server EusOperating system
Affected:= 7.3= 7.4= 7.5
Enterprise Linux WorkstationOperating system
Affected:= 6.0= 7.0

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
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

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.

dbcve · scoped
Patch available Apply the vendor patch
Vendor patch lists.gnu.org →
Recommended fix High confidence

Upgrade to QEMU 2.8.0 or later (or apply vendor-supplied security errata that includes the QEMU 2.8+ fix for this vulnerability)

  1. 1. Identify the QEMU version currently in use: Run `rpm -q qemu-kvm` or `qemu-system-x86_64 --version` to confirm the vulnerable version.
  2. 2. For Red Hat Enterprise Linux systems: Apply the Red Hat Security Advisory RHSA-2017:0293 or subsequent errata that addresses CVE-2017-2620. Run `yum update qemu-kvm` or `yum update qemu-kvm-rhev` to apply the fix.
  3. 3. For Debian systems: Update the qemu package by running `apt-get update && apt-get install qemu-kvm` or `apt-get upgrade` to obtain a version containing the fix.
  4. 4. For XenServer: Apply the appropriate XenServer security patch that includes the QEMU 2.8+ update, or upgrade to XenServer 7.0 or later which contains the fixed QEMU version.
  5. 5. For OpenStack: Apply the relevant security errata for your OpenStack version, or upgrade to a newer OpenStack release that includes QEMU 2.8 or later.
  6. 6. After updating, restart the QEMU processes or the virtual machines to ensure the patched version is loaded.
  7. 7. Verify the fix by checking the QEMU version: `rpm -q qemu-kvm` and confirm it is version 2.8.0 or higher, or check for the specific security advisory applied.
Caveat Upgrading QEMU may require restarting virtual machines. Some guest operating systems may require adjustment for hardware changes in the emulated video adapter.

Generated from the published advisory — verify against the referenced sources before acting.

We can apply and verify the patch for your build — typical engagement from $3,550. Get the patch applied

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2017-2620 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2017-2620 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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