XenOperating system

CVE-2013-2077

MEDIUM · 5.2 CVSS v2.0 Published 2013-08-28
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
54/100
Remediation priority · Moderate
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
Xen 4.0.x, 4.1.x, and 4.2.x does not properly restrict the contents of a XRSTOR, which allows local PV guest users to cause a denial of service (unhandled exception and hypervisor crash) via unspecified vectors.

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 · high confidence

Xen hypervisor versions 4.0.x through 4.2.x fail to properly validate or restrict the contents handled by the XRSTOR instruction (x87 FPU state restore). This allows local paravirtualized guest users to trigger an unhandled exception by supplying malicious input to XRSTOR, causing the hypervisor to crash and resulting in a denial of service for all guests on the host.

MitigationApply the relevant Xen security patch (or upgrade to a patched Xen version) to properly validate XRSTOR operations. As a temporary measure, consider isolating untrusted PV guests or limiting their privileges until the patch can be applied.

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
XenOperating system
Affected:= 4.0.0= 4.0.1= 4.0.2= 4.0.3= 4.0.4= 4.1.0= 4.1.1= 4.1.2= 4.1.3= 4.1.4= 4.1.5= 4.2.0

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
Adjacent
Complexity
M
Authentication
Single
Confidentiality
None
Integrity
None
Availability
Complete

AV:A/AC:M/Au:S/C:N/I:N/A:C

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 the installed Xen hypervisor version
    Run 'xm info' or 'xl info' and look for the 'xen_version' field, or check the output of 'uname -r' on the dom0 kernel if applicable
    Affected if The version falls within 4.0.0 through 4.2.0 (specifically 4.0.0, 4.0.1, 4.0.2, 4.0.3, 4.0.4, 4.1.0, 4.1.1, 4.1.2, 4.1.3, 4.1.4, 4.1.5, 4.2.0)
  2. Determine if paravirtualized (PV) guests are running
    List all running domains using 'xl list' or 'xm list' and check the 'type' column for 'pv' (paravirtualized) domains. PV domains are identified by not using HVM (hardware virtual machine) type
    Affected if PV guests are actively running on the Xen host
  3. Verify x87 FPU state restore operations are in use
    Monitor for XRSTOR instruction usage within PV guest contexts. This can be observed through hypervisor logging or by checking if PV guest workloads involve x87 floating-point operations
    Affected if PV guests are performing x87 FPU state restore operations using the XRSTOR instruction

If the Xen hypervisor version is 4.0.0 through 4.2.0 AND paravirtualized guests with x87 FPU operations are running, the environment is affected by this vulnerability.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the relevant Xen security patch (or upgrade to a patched Xen version) to properly validate XRSTOR operations. As a temporary measure, consider isolating untrusted PV guests or limiting their privileges until the patch can be applied.

Fix this in Xen Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2013-2077 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
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