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CVE-2018-7540· NVD / CVE Program· CNA mitre

An issue was discovered in Xen through 4.10.x allowing x86 PV guest OS users to cause a denial of service (host OS CPU hang) via non-preempt

An issue was discovered in Xen through 4.10.x allowing x86 PV guest OS users to cause a denial of service (host OS CPU hang) via non-preemptable L3/L4 pagetable freeing.

MediumCVSS 6.5 · v3.0—No exploit Fix available
Published
Feb 27, 2018
Updated
Jun 16, 2026
EPSS
0.4% · 34th percentile
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Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

Affected systems

VendorProduct
xenxen
debiandebian linux

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • debian debian linux9.0
  • xen xenup to 4.10.0 inclusive

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.10xenbefore 4.10.0-r24.10.0-r2
Alpine:v3.4xenbefore 4.6.3-r44.6.3-r4
Alpine:v3.5xenbefore 4.7.3-r74.7.3-r7
Alpine:v3.6xenbefore 4.8.2-r64.8.2-r6
Alpine:v3.7xenbefore 4.9.1-r44.9.1-r4
Debian:12xenbefore 4.8.3+comet2+shim4.10.0+comet3-1+deb9u54.8.3+comet2+shim4.10.0+comet3-1+deb9u5
Debian:7xenbefore 4.1.6.lts1-134.1.6.lts1-13
Debian:8xenbefore 4.4.4lts4-0+deb8u14.4.4lts4-0+deb8u1
SUSE:Linux Enterprise Desktop 12 SP2xenbefore 4.7.5_02-43.27.14.7.5_02-43.27.1
SUSE:Linux Enterprise Desktop 12 SP3xenbefore 4.9.2_04-3.29.14.9.2_04-3.29.1
SUSE:Linux Enterprise Point of Sale 11 SP3xenbefore 4.2.5_21-45.19.14.2.5_21-45.19.1

Same product

xen: all records

Other highest-scoring records for the same primary product.

  • CVE-2017-10921The grant-table feature in Xen through 4.8.x does not ensure sufficient type counts for a GNTMAP_device_map and GNTMAP_host_map mapping, whi
    41Plan
  • CVE-2017-10920The grant-table feature in Xen through 4.8.x mishandles a GNTMAP_device_map and GNTMAP_host_map mapping, when followed by only a GNTMAP_host
    41Plan
  • CVE-2017-10918Xen through 4.8.x does not validate memory allocations during certain P2M operations, which allows guest OS users to obtain privileged host
    41Plan
  • CVE-2017-10912Xen through 4.8.x mishandles page transfer, which allows guest OS users to obtain privileged host OS access, aka XSA-217.
    41Plan
  • CVE-2015-8104The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a denial of service (host O
    41Plan
  • CVE-2015-5165The C+ mode offload emulation in the RTL8139 network card device model in QEMU, as used in Xen 4.5.x and earlier, allows remote attackers to
    41Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
alpine:xen4.10.0-r2 · Alpine:v3.10Package registry (OSV)
debian:xen4.8.3+comet2+shim4.10.0+comet3-1+deb9u5 · Debian:12Package registry (OSV)
suse:xen4.2.5_21-45.19.1 · SUSE:Linux Enterprise Point of Sale 11 SP3Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality impact
None
Integrity impact
None
Availability impact
High

CVSS vector

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

nvd-primary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
function expand(node) {  return node.children.map(expand);}

Fixed

ts
const MAX_DEPTH = 32;function expand(node, depth = 0) {  if (depth > MAX_DEPTH) throw new Error("too deep");  return node.children.map((c) => expand(c, depth + 1));}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

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Change log

  1. Fix✗ → ✓

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References

All records