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TI-2019-13410 Aliases CVE-2019-18420GHSA-54p2-qq73-f565

An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to cause a…

Priority LOW 34CWE-134Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-134 and the CVSS impact.

Summary

An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to cause a denial of service via a VCPUOP_initialise hypercall. hypercall_create_continuation() is a variadic function which uses a printf-like format string to interpret its parameters. Error handling for a bad format character was done using BUG(), which crashes Xen. One path, via the VCPUOP_initialise hypercall, has a bad format character. The BUG() can be hit if VCPUOP_initialise executes for a sufficiently long period of time for a continuation to be created. Malicious guests may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen versions 4.6 and newer are vulnerable. Xen versions 4.5 and earlier are not vulnerable. Only x86 PV guests can exploit the vulnerability. HVM and PVH guests, and guests on ARM systems, cannot exploit the vulnerability.

Why it matters now

EPSS 0.02911 87th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 6

CPEVersionsRoleVendor
cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:*up to 4.12.1VulnerableXen
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*9.0VulnerableDebian
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*10.0VulnerableDebian
cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:*29VulnerableFedoraproject
cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*30VulnerableFedoraproject
cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*31VulnerableFedoraproject
  • cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:* Versions up to 4.12.1 Vulnerable ·Xen
  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
  • cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
  • cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:* Versions 29 Vulnerable ·Fedoraproject
  • cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:* Versions 30 Vulnerable ·Fedoraproject
  • cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:* Versions 31 Vulnerable ·Fedoraproject

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat Enterprise Linux 5

Timeline

  1. 2026-10-02 Threatist record created from CVE-2019-18420
  2. 2026-10-03 Alias added: GHSA-54p2-qq73-f565

References

Patch 2

Advisory 7

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences