CVE-2015-4164: Xen

Medium severity, CVSS 4.9. EPSS: 0.4% chance of exploitation in the next 30 days.

The compat_iret function in Xen 3.1 through 4.5 iterates the wrong way through a loop, which allows local 32-bit PV guest administrators to cause a denial of service (large loop and system hang) via a hypercall_iret call with EFLAGS.VM set.

Affected products

• Xen Xen: version 3.1.3 only; version 3.1.4 only; version 3.2.0 only; version 3.2.1 only; version 3.2.2 only; version 3.2.3 only; …

Published 2015-06-15. Last modified 2026-06-17.